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Manual de Plantas de Costa Rica

Main | Family List (MO) | Family List (INBio) | Cutting Edge
Draft Treatments | Guidelines | Checklist | Citing | Editors

Draft Treatments

ARACEAE
By M. H. Grayum
English, final draft: placed 1/May/2000

Pistia

Engler, A. 1920. Aroideae und Pistioideae. In A. Engler (ed.), Das Pflanzenreich IV.23.F (Heft 73): 1-274. Engelmann, Berlin.

1 polytypic sp., throughout trop. and subtrop. regions of world.

Pistia stratiotes L., Sp. pl. 963. 1753. Lechuga de agua.

Floating, stoloniferous aquatics (occasionally stranded), lacking milky sap. Roots plumose. Leaves spiraled in dense rosettes. Petioles obsolete or to ca. 3 cm long, flattened to terete, often hirsute. Leaf-blades ca. 0.6-17 × 0.8-8 cm, subreniform or ovate to (more frequently) obovate, obdeltate, or oblanceolate, broadly rounded to truncate apically, ± spongy, pilosulous on both sides, with 3-15 prominent, subparallel veins becoming plicate below. Infls. solitary in axils, small and inconspicuous; peduncle ca. 2.5-6 mm long, pubescent; spathe ca. 5-6.5 mm long, pubescent externally, with proximal tube and distal, whitish lamina; spadix mostly adnate to spathe, with separate male and female regions, without sterile zones. Fls. unisexual, naked; male fls. 2-8 in a terminal verticel, with 2 stamens connate in synandria; female fls. solitary, with short style; stigma obtuse; ovary unilocular; ovules numerous, borne along parietal placentae. Frs. thin-walled, ca. 4-13-seeded. Seeds ca. 2.5 × 1.5 mm, barrel-shaped, truncate at each end, pitted, operculate.

Lagoons, canals, swamps, and rice-fields, 0-100(-750) m; N Atl. slope (P.N. Tortuguero, Lago Arenal), entire Pac. slope. Fl. Aug.-Oct. (Grayum & Sleeper 5933; CR, MO)

Robust specimens of this familiar sp. are unmistakable by virtue of their floating habit and erect, short-petioled, rosette-forming leaves with fleshy, cuneate-based, parallel-veined blades. The tiny, axillary infls. are very inconspicuous. The plants are exceedingly variable in leaf-blade size and shape, sometimes within a single population; even the smallest specimens (with subreniform or ovate, 3-veined leaf-blades < 1 × 1 cm) may be fertile. Such presumably precocious individuals might be mistaken for Spirodela (Lemnaceae) or Salvinia (Pteridophyta, Salviniaceae).

Pistia stratiotes is occasionally planted as an ornamental in aquaria and ponds.

Rhodospatha

Engler, A. & K. Krause. 1908. Monsteroideae. In A. Engler (ed.), Das Pflanzenreich IV.23 (Heft 37): 4-138. Engelmann, Berlin.

Ca. 67 spp., S Mex. to Bol., Guianas, S Braz., Trin.; 9 spp. in CR.

Terrestrial plants or (more commonly) appressed-climbing hemiepiphytes; stems usually ± stout, in terrestrial spp. decumbent to weakly erect, sometimes supported by prop roots; plants lacking milky sap. Leaves distichous. Petioles never peltately attached, with a geniculum. Leaf-blades simple, narrowly lanceolate to broadly ovate, often pinkish when flushing, the margins entire. Infls. solitary in leaf (or cataphyll) axils; spathe erect and enveloping spadix at anthesis, white to pinkish, without a proximal tube, becoming broadly splayed and promptly deciduous; spadix uniform, lacking sterile fls. toward base. Fls. bisexual, naked; stamens 4, distinct; style thickened, shorter than ovary; stigma linear or (rarely) 2- or 3-lobed; ovary 2-locular; ovules numerous per locule, borne along axile placentae. Frs. many-seeded. Seeds 1-1.6 mm long, reniform to lenticular.

Rhodospatha closely resembles Monstera, from which it differs principally in having numerous and small (as opposed to few and large) ovules and seeds. Furthermore, leaf-blades in Rhodospatha are always entire and imperforate, while they are often pinnatifid and/or perforate in Monstera. Despite the generic name, most CR Rhodospatha spp. do not have pinkish spathes (and some Monstera spp. do!). Terrestrial spp. of Rhodospatha may closely resemble Spathiphyllum, but the latter genus differs in having persistent spathes and perigoniate fls.

1 Plants terrestrial; petioles usually sheathed for < 2/3 of the way to the leaf-base; rare plants of the Atl. slope.

2 Leaf-blades 31-80 cm, ± narrowly elliptical, with 25-38 primary lateral veins per side, these usually > 1 cm apart; peduncles 20-50.5 cm...R. moritziana

2' Leaf-blades 25-46 cm, ovate to broadly elliptical or subrotund, with 32-57 primary lateral veins per side, these usually < 1 cm apart; peduncles 9.5-29 cm...R. sp. A

1' Plants epiphytic; petioles usually sheathed to > 2/3 of the way to the leaf-base; both slopes.

3 Primary lateral leaf veins < 25 per side; petiole sheaths persistent.

4 Petioles > 25 cm; leaf-blades > 12 cm wide; 1500-1600 m...R. sp. B

4' Petioles < 25 cm; leaf-blades < 12 cm wide; 0-1200 m.

5 Petioles sheathed to geniculum; leaf-blades dull on both surfaces; 50-100 m, Atl. slope...R. sp. C

5' Petioles sheathed to base of leaf-blade (with free portion of sheath often prolonged beyond it); leaf-blades glossy above, semiglossy below; 0-1200 m, Pac. slope...R. sp. D

3' Primary lateral leaf veins with > 25 per side (on at least some larger leaves); petiole sheaths persistent or deciduous.

6 Petioles 7-25 cm, < 65% length of blade; leaf-blades with primary lateral veins closely flanked by dark files of pellucid glandular streaks, these sometimes scattered to abundant in intervenal spaces; 0-650 m, Atl. slope...R. pellucida

6' Petioles (12-)20-83 cm, > 65% length of blade; leaf-blades lacking pellucid glandular streaks; 0-1500 m, both slopes.

7 Petiole sheaths persistent; leaf-blades drying yellow-green to bright green, with 25-33 primary lateral veins per side; spathe dull pinkish within at anthesis...R. forgetii

7' Petiole sheaths deciduous; leaf-blades drying brownish to blackish, with (17-)24-52(-70) primary lateral veins per side; spathe whitish to pinkish or purplish within at anthesis.

8 Stems drying longitudinally fissured; petioles (13-)30-83 cm; leaf-blades (23.5-)36-75 × (8.8-)15-35 cm, with 28-52(-70) primary lateral veins per side; peduncles 9-30 cm; spadix (7.3-)13.2-26.2 cm; 0-1500(-1750+) m, both slopes...R. wendlandii

8' Stems drying transversely fissured; petioles (12-)20-36 cm; leaf-blades (23-)30-51 × (7.5-)8-15 cm, with (17-)24-32 primary lateral veins per side; peduncles 13-21 cm; spadix 8.8-15.1 cm; 500-1200+ m, Atl. slope...R. sp. E

Rhodospatha forgetii N. E. Br., Bull. Misc. Inform. Kew 1913: 358. 1913.

Scandent plants. Petioles ca. 29.5-45 cm, sheathed to within ca. 2-6.5 cm of geniculum, the sheath apparently persistent. Leaf-blades ca. 41.5-60 × 13.9-20 cm, narrowly elliptical, "somewhat shining", with ca. 25-33 primary lateral veins per side. Peduncles ca. 10.5-16.5(-30) cm. Spathe at first dull (salmon) pinkish within, latter fading to dull yellow. Spadix ca. 10.4-12 × 0.9-1.4 cm, at first pale pinkish, the stipe ca. 0.5-1.5 cm. Ripe frs. unknown.

"Plant sent from Costa Rica by Mr. Forget" (2 Aug. 1913, Hort. Sander & Sons s. n., K).

Rhodospatha forgetii is known only from two herbarium specimens prepared from material in cult.: the holotype, from a plant grown at Kew (cited above), and a later collection from a plant grown at Edinburgh and probably propagated from the Kew material. These original specimens do not correspond convincingly to any wild-collected material, from CR or anywhere else. Probably the best match, among CR spp., is Rhodospatha moritziana, which differs primarily in being terrestrial.

Forget's itinerary in CR is unknown; indeed, there appears to be no independent evidence that he even visited the country. Thus, not only is the identity of R. forgetii nebulous, its occurrence in CR must also be regarded with suspicion.

Rhodospatha moritziana Schott, Oesterr. Bot. Wochenbl. 7: 109. 1857. Anepsias moritzianus (Schott) Schott.

Terrestrial or ± epilithic, often along creeks. Petioles ca. 23-69 cm, sheathed < halfway or to within 2 cm of geniculum, the sheath densely whitish-speckled, ± persistent. Leaf-blades ca. 31-80 × 14.5-34 cm, ± narrowly elliptical, ± glossy above, matte and ± whitish below, with ca. 25-38 primary lateral veins per side. Peduncles ca. 20.5-50.5 cm. Spathe lilac-pink (very early) to greenish white or cream-colored. Spadix ca. 8-15.7 × 0.9-2 cm, salmon-pink to lilac at anthesis, becoming greenish, the stipe ca. 1-2.3 cm. Ripe frs. yellow-orange.

Wet forests, 100-400 m; Atl. slope Cord. Talamanca. Fl. Jun., Sep. CR to Amaz. Per˙ and W Ven. (Grayum et al. 8747; CR, MO)

Rhodospatha moritziana is distinct among all CR Rhodospatha spp. in its terrestrial habit and relatively narrow leaf-blades. Due to this combination of features, it is perhaps more liable to be mistaken for a Spathiphyllum sp. This is an uncommon sp. in CR, where it is not known from any easily accessible sites.

The name Anepsias moritzianus was certainly misapplied by Standley (1937), although to what sp. is unclear.

Rhodospatha pellucida Croat & Grayum, in Croat, Novon 9: 500. 1999.

Appressed-climbing or loosely scandent, epiphytic vines, usually fertile ca. 2-2.5 m above the ground. Petioles 7-25 cm, sheathed to within 4 cm of the blade, the sheath persistent. Leaf-blades 13.5-43 × 4.5-15.8 cm, narrowly elliptical to oblong-lanceolate or oblanceolate, glossy above, weakly glossy to semiglossy and markedly paler below, with ca. 18-40 primary lateral veins per side. Peduncles ca. 6.7-29.5 cm. Spathe cream-colored to white within. Spadix ca. 5.3-16 × 0.7-1.2 cm, cream-colored to white at anthesis, the stipe ca. 0.5-1.5 cm. Color of ripe frs. unknown (spadix becoming bluish or olive-green post anthesis).

Wet forests, 0-650 m; entire Atl. slope. Fl. Apr.-Sep., Nov. Extreme SE Nic. to Pac. Ecua. (Grayum 9845; CR, MO)

Rhodospatha pellucida comprises smallish, nondescript plants, recognized by their Atl. slope habitat, epiphytic habit, relatively short petioles, and numerous (> 25 pairs) primary lateral leaf veins flanked by pellucid streaks. These streaks may be very conspicuous and scattered throughout the intervenal spaces (as particularly in the Sixaola region), or inconspicuous and restricted to a single, closely appressed file on either side of each primary vein.

Rhodospatha wendlandii Schott, J. Bot. 2: 52. 1864. R. nervosa Lundell.

Appressed-climbing trunk epiphytes, fertile ca. 2-4 m above the ground. Petioles ca. (13-)30-83 cm, sheathed to within 7 cm of the geniculum, the sheath deciduous. Leaf-blades ca. (23.5-)36-75 × (8.8-)15-35 cm, lance-ovate to narrowly elliptical or oblong-lanceolate, often truncate at base, matte to glossy above, semiglossy and paler below, with ca. 28-52(-70) primary lateral veins per side. Peduncles ca. 9-30 cm. Spathe white or cream to pinkish or purplish within. Spadix (7.3-)13.2-26.2 × 0.9-2 cm, pinkish to purplish or reddish at anthesis, the stipe ca. 0.5-2.1(-2.6) cm. Ripe frs. pale yellow or yellow-orange.

Wet forests, 0-1500(-1750+) m; Atl. slope and near Continental Divide, all major cords. (to R.N.F.S. Barra del Colorado and P.N. Tortuguero), Pac. slope Cord. Guanacaste, and S from R.B. Carara. Fl. Jan., Mar., May-Oct., Dec. S Mex. (Oax., Ver.) to Pac. Col. (Davidse et al. 28427; CR, MO)

This is the most widespread and well-known CR Rhodospatha sp., easily identified by its epiphytic habit, relatively long petioles with deciduous sheaths, and large, often truncate-based, many-veined leaf-blades. It can only be confused with the smaller and rarer R. sp. E (see key, couplet 8), the only other epiphytic Rhodospatha sp. in CR with deciduous petiole sheaths. The spathes of Rhodospatha wendlandii are typically white or whitish in CR, but may be pink to purplish in some localities (Cord. Guanacaste). The spadix is usually nodding in fr.

Rhodospatha sp. A

Terrestrial, the stems ± decumbent to long-creeping, with erect portion to ca. 1.5 m tall and supported by long prop-roots. Petioles ca. 23-70 cm, sheathed for ca. 3/5 to 2/3(-9/10) their total length, the sheath deciduous. Leaf-blades ca. 25-46 × 12-31.5 cm, ovate to broadly elliptical or subrotund, weakly glossy to semiglossy on both surfaces, with ca. 32-57 primary lateral veins per side, these prominently sunken above and raised below. Peduncles 9.5-29 cm. Spathe cream-colored (Liesner 14420, MO). Spadix ca. 6.7-18 × 0.9-1.8 cm, color not reported, the stipe ca. 1.5-3 cm. Color of ripe frs. unknown.

Wet forests, often in rocky sites, 140-1200+ m; Atl. slope Cords. Central and Talamanca. Fl. Apr., Jun., Jul. CR and W Pan. (Liesner 14420; CR, MO)

This sp. is easily recognized by its terrestrial habit and relatively broad leaf-blades with numerous, prominent primary lateral veins. Rhodospatha sp. A is generally rare in CR, though it may be locally abundant.

Rhodospatha sp. B

Loosely scandent trunk epiphytes to at least 2.5 m above the ground, the stem epidermis glossy. Petioles ca. 38-47 cm, glossy, sheathed to geniculum, the sheath persistent. Leaf-blades ca. 43-51 × 15.5-19 cm, ± narrowly elliptical, glossy and dark green above, glossy or semiglossy and much paler below, with 16-20 primary lateral veins per side. Fertile parts unknown.

Wet (cloud) forest, 1500-1600 m; Atl. slope Cord. Central (Río Zurquí). Fl. ? CR and W Pan., possibly Col. (Grayum & Sleeper 6137; INB, MO)

This sp. is distinguished by its cloud-forest habitat, persistent petiole sheaths, and relatively large, glossy, leaf-blades with few (< 25 pairs) primary lateral veins. Although known from CR by just one, sterile collection, it is not confused with any other sp.

Rhodospatha sp. C

Epiphytes. Petioles ca. 13.5-19.5 cm, sheathed to geniculum, the sheath apparently persistent. Leaf-blades ca. 21.5-27 × 3.4-5.5 cm, narrowly lanceolate, "dull on both sides" (McPherson 10833, MO; Pan.), with 16-22 primary lateral veins per side. Peduncles ca. 8-10 cm. Spathe "green-white" (McPherson 10833). Spadix ca. 5.8-6.9 × 0.6-0.7 cm, "pale whitish-green" (Burger & Antonio 10924), the stipe ca. 0.8 cm. Ripe frs. unknown.

Wet forests, 50-100 m; Atl. slope Cord. Talamanca (between Puerto Viejo de Talamanca and Bribrí). Fl. Sep. CR and adjacent Pan. (Burger & Antonio 10924, F)

Rhodospatha sp. C, a rare sp. of the Sixaola region, is distinguished by its epiphytic habit and relatively small leaf-blades with few (< 25 pairs) primary lateral veins. It is most similar to the Pac. slope R. sp. D (see key, couplet 5).

Rhodospatha sp. D

Epiphytic vines on trunks, fertile ca. 2.5-5 m above the ground. Petioles ca. 4.3-19.5 cm, sheathed to within 3 mm of blade (sheath often prolonged beyond blade base), the sheath erect to involute, persistent. Leaf-blades ca. 13-41 × 2.7-9.4 cm, narrowly elliptical or oblong-lanceolate to oblanceolate, glossy and dark green above, semiglossy and yellow-green below, with 7-22 primary lateral veins per side. Peduncles ca. 8-19 cm. Spathe pure white within. Spadix ca. 4.3-11.7 × 0.6-1.1 cm, cream-colored, the stipe ca. 0.1-1.3 cm. Ripe (?) frs. blue-green.

Wet forests, 0-1200 m; Pac. slope S from R.B. Carara and Z.P. Cerros de Turrubares. Fl. Jan., Apr.-Sep., Dec. ENDEMIC. (Grayum et al. 7574; CR, MO)

Rhodospatha sp. D is a distinctive sp., easily recognized by its Pac. slope habitat, epiphytic habit, relatively short, fully sheathed petioles, and narrow leaf-blades highly glossy above. It is most similar to the Atl. slope R. sp. C (see key, couplet 5). This sp. is especially common in the forest at J.B. Wilson.

Rhodospatha sp. E

More or less appressed-climbing trunk epiphytes, fertile ca. 2+ m above the ground, the stems drying transversely fissured. Petioles ca. (12-)20-36 cm, sheathed to within 4.5 cm of the blade, the sheath deciduous. Leaf-blades ca. (23-)30-51 × (7.5-)8-15 cm, narrowly elliptical to oblong-lanceolate or oblanceolate, ± velvety above, weakly glossy and pallid green ("silvery") below, with ca. (17-)24-32 primary lateral veins per side. Peduncles ca. 13-21 cm. Spathe cream-colored within. Spadix ca. 8.8-15.1 × 0.7-1.7 cm, pinkish cream at anthesis, the stipe ca. 0.6-1.2 cm. Color of ripe frs. not certainly known.

Wet forests, ca. 500-1200+ m; Atl. slope Cords. Tilarán, Central, and Talamanca. Fl. Jan., Mar., Apr., Jul. CR to W cent. Pan. (Grayum 6707; CR, MO)

Rhodospatha sp. F is characterized by an epiphytic habit, deciduous petiole sheaths, and numerous (> 25 pairs) primary lateral leaf veins. It can only be confused with the generally larger and more widespread R. wendlandii (see key, couplet 8).

Spathiphyllum

Baker, R. A. & W. C. Burger. 1976. Key and commentary on the species of Spathiphyllum (Araceae) in Costa Rica, including S. silvicola, sp. nov. Phytologia 33: 447-454.

Ca. 60 spp. in the Neotropics, from Mex. (Ver.) to Per˙ and NE Braz., plus 3 spp. in E Indonesia and SW Pac. region; 8 spp. in CR.

Terrestrial, acaulescent plants (some Asian spp. may be appressed-climbing, with ± evident stems); plants lacking milky sap. Leaves distichous. Petioles never peltately attached, with a geniculum. Leaf-blades simple, narrowly lanceolate to broadly elliptical or subovate, the margins entire. Infls. solitary in axils; spathe deflexed and ligulate to erect and broadly splayed at anthesis, without a proximal tube, white to yellowish, persistent; spadix uniform, lacking sterile fls. toward base, the stipe sometimes adnate to spathe for some or all of its length. Fls. bisexual, with perianth of (4)6 distinct or connate tepals; stamens (4)6, distinct; style obsolete to thickened, conical, and conspicuously exserted; stigma 3-4-lobed; ovary (2)3(4)-locular; ovules (1-4)6-8 per locule, on axile placentae. Frs. usually white or whitish, few- to several-seeded.

Spathiphyllum is usually easily recognized by its terrestrial, acaulescent habit, ± lanceolate to elliptical, non-cordate leaf-blades with numerous primary lateral veins, and long-pedunculate infls. with persistent spathes and perigoniate, bisexual fls. In CR, it can only be confused with some terrestrial spp. of Anthurium (see, especially, A. lancifolium) and Rhodospatha (with caducous spathes and naked fls.). Several Spathiphyllum spp. exhibit extreme variation in the size of flowering specimens.

1 Spathe 1.4-5.1 cm wide, lanceolate or lance-ovate to narrowly elliptic, lance-oblong, or oblanceolate, becoming reflexed, non-decurrent on peduncle or decurrent to 2.4 cm.

2 Tepals fully connate in a cupulate perianth, the margins entire; both slopes...S. laeve

2' Tepals distinct, or connate only in basal half, the perianth margins incised.

3 Leaf-blades 30-46 × 12.3-22 cm, with ca. 18-32 primary lateral veins per side; petioles usually ± densely asperulous with minute, stellate trichomes; spathe usually non-decurrent on peduncle (rarely decurrent to ca. 1.1 cm); spadix at anthesis ca. 7.4-15.1 cm; tepals distinct; Atl. slope...S. fulvovirens

3' Leaf-blades 15-38.5 × 4.5-11.5(-15.3) cm, with ca. (9-)12-23 primary lateral veins per side; petioles always glabrous; spathe decurrent on peduncle for 0.4-1.4 cm; spadix at anthesis ca. 3.6-7.5 cm; tepals connate in proximal half; Pac. slope...S. silvicola

1' Spathe 2.7-12 cm wide, lance-ovate or narrowly or broadly elliptic to oblanceolate or obovate, erect in all stages, decurrent on peduncle for 1.5-16.5 cm.

4 Petioles shorter than blades, the sheath reaching the geniculum; spathe white at anthesis; styles exserted; 0-1150 m, both slopes...S. wendlandii

4' Petioles (at least on larger leaves) longer than blades, the sheath not reaching the geniculum; spathe white or green at anthesis; styles obsolete to exserted; 0-2000 m, both slopes.

5 Petioles sheathed < halfway to leaf-base; ovary truncate at apex, the style obsolete (to ca. 0.5 mm long); spathe pale green at anthesis...S. atrovirens

5' Petioles sheathed (3/8-)2/5-15/16 to leaf-base; ovary attenuate at apex, the style conspicuously exserted, ca. 0.5-6 mm long; spathe white or green at anthesis.

6 Leaf-blades 30-63 cm long; peduncles 48-142 cm; spathe white at anthesis, decurrent on peduncle for 1.5-5.5 cm; styles 3-6 mm long, subcylindric, ± uniformly thickened (except at apex); seeds commonly 12-24; ± open, wet sites (pastures or marshes), 0-150 m, Atl. slope...S. friedrichsthalii

6' Leaf-blades 20-47.5(-53) cm long; peduncles 15.5-105(-119) cm; spathe white or green at anthesis, decurrent on peduncle for (3-)3.2-8.2 cm; styles 0.5-2.5(-4.5) mm long, conical, gradually broadened toward base; seeds always < 12; primary or secondary forest, 0-2000 m, both slopes.

7 Petioles (22.5-)27-52(-80) cm; peduncles 15.5-61.5(-119) cm; spathe white (or sometimes green?) at anthesis; spadix at anthesis 2.4-4.5(-10) cm; 1100-2000 m, both slopes...S. montanum

7' Petioles 16.5-95 cm; peduncles 35-105 cm; spathe green (never white) at anthesis; spadix at anthesis (2-)3.3-9.5 cm; 0-1100 m, both slopes...S. phryniifolium

Spathiphyllum atrovirens Schott, Oesterr. Bot. Z. 8: 179. 1858.

Petioles ca. 22-111 cm, sheathed < halfway to leaf-base on larger leaves. Leaf-blades 27-59 × 9.5-25.5 cm, narrowly or broadly elliptical to lanceolate, lance-ovate or oblong-lanceolate, broadly cuneate to rounded or subtruncate at base (but usually ± attenuate at petiole apex), with ca. 17-38 primary lateral veins per side. Peduncles ca. 33.5-102 cm. Spathe ca. 11-38 × 4.3-12 cm, narrowly to broadly elliptical to oblanceolate or obovate, pale green at anthesis, decurrent on peduncle ca. 2.5-16.5 cm. Spadix at anthesis ca. 2.9-5.9 × 0.6-0.9 cm, white or greenish white, on stipe ca. 0.5-2.3 cm. Tepals distinct. Ovary subtruncate at apex, the style obsolete (to ca. 0.5 mm long). Color of ripe frs. unknown.

Wet forests, often near streams or springs or in open, marshy sites, (300?-)600-1700 m; both slopes Cords. Tilarán and Central, Pac. slope Cord. Talamanca. Fl. Jan.-Mar., May-Aug., Oct. CR and extreme W Pan. (Z. Fuentes 624; INB, MO)

This is our only Spathiphyllum sp. with broad, erect, long-decurrent spathes that does not have conspicuously exserted styles. It is further characterized by its greenish spathes and smallish spadices. Spathiphyllum atrovirens is rare and spottily distributed throughout its range.

Spathiphyllum friedrichsthalii Schott, Aroideae 1: 2, t. 4. 1853.

Petioles ca. 33-104 cm, mostly sheathed 1/2-3/4 to leaf-base on larger leaves. Leaf-blades 30-63 × 8.6-23 cm, ± narrowly elliptical, narrowly to broadly cuneate (sometimes ± attenuate) at base, with ca. 14-29 primary lateral veins per side. Peduncles ca. 48-142 cm. Infls. sweetly aromatic at anthesis. Spathe ca. 12.5-32 × 4.2-11 cm, ± narrowly elliptical, white at anthesis (later becoming yellow-green), decurrent on peduncle ca. 1.5-5.5 cm. Spadix at anthesis ca. 3.4-8.4 × 0.9-2 cm, white, subsessile or on stipe to ca. 1.3 cm. Tepals distinct. Styles elongate-exserted, subcylindric, ca. 3-6 mm long. Ripe frs. apparently green.

Wet forests, in open marshes or (secondarily) pastures, 0-150 m; entire Atl. slope. Fl. Feb.-Jul., Sep., Nov. S Mex. (Tab., Yuc.) and Hond. to Pac. Col. (Gómez et al. 20508; CR, MO)

Spathiphyllum friedrichsthalii is most easily recognized by its habitat: open, marshy sites below 200 m elevation on the Atl. slope. It is the only CR Spathiphyllum spp. found in such places. On herbarium sheets, S. friedrichsthalii is best recognized by its blackish-drying foliage, broad, erect, decurrent spathes, and subcylindric (rather than conical) styles. This is our most familiar Spathiphyllum spp., as it grows abundantly in wet pastures and is conspicuous even from speeding autos by virtue of its broad, white flowering spathes. It has also been cult. for the cut-flower and house-plant trades, under the English name peace lily.

Spathiphyllum fulvovirens Schott, Oesterr. Bot. Z. 8: 179. 1858.

Petioles ca. 46-74 cm, sheathed ca. (1/3-)1/2-2/3 to leaf-base, usually ± densely stellate-asperulous (especially on sheath). Leaf-blades 30-46 × 12.3-22 cm, narrowly elliptical to subovate, cuneate to rounded at base, with ca. 18-32 primary lateral veins per side. Peduncles ca. 60-107 cm. Spathe ca. 9-18 × 1.4-5.1 cm, narrowly elliptical to lanceolate, oblanceolate or (rarely) lance-ovate, white or greenish white at anthesis (later becoming green), mostly non-decurrent, occasionally decurrent on peduncle to ca. 1.1 cm. Spadix at anthesis ca. 7.4-15.1 × 0.4-0.7 cm, green (tepals) to white (pistils), on stipe ca. 0.2-1(-1.5) cm. Tepals distinct. Style obsolete. Ripe frs. uniformly white.

Wet forests, 0-250(-350?) m; Atl. slope Cord. Central (Volcán Barva), to R.N.F.S. Barra del Colorado and P.N. Tortuguero. Fl. Jan.-Mar., May-Oct. SE Nic. to Col. (Pac. slope and Río Magdalena Valley). (Robles 1614; CR, MO)

Spathiphyllum fulvovirens is distinguished by its stellate-asperulous petioles and ± narrow, reflexed, usually non-decurrent spathes. It is most similar to the sympatric S. laeve and the Pac. slope S. silvicola, both of which comprise smaller plants with glabrous petioles and briefly decurrent spathes. The former sp. differs additionally in its fully connate tepals. Though locally common in primary forest, S. fulvovirens is of restricted distribution in CR; it has been collected much more frequently in Pan., where it ascends to at least 1000 m elevation.

The peculiar stellate petiolar trichomes, unique to S. fulvovirens (at least among CR spp.), have not been mentioned by previous authors. Unfortunately, they are not manifest on every specimen.

Spathiphyllum laeve Engl., Bot. Jahrb. Syst. 37: 120. 1905.

Petioles ca. 20.5-65 cm, sheathed ca. 1/2-2/3 to leaf-base, the geniculum usually brownish. Leaf-blades 15-38 × 5.4-14.2 cm, narrowly elliptical to lance-ovate or (rarely) obovate, cuneate to (less frequently) rounded at base, with ca. 15-25 primary lateral veins per side. Peduncles ca. 48.5-103 cm. Spathe ca. 8-25 × 2.1-5 cm, lance-oblong or (less frequently) lanceolate to narrowly elliptical, green or yellow-green at anthesis, decurrent on peduncle 0.5-2.4 cm. Spadix at anthesis 4-16.5 × 0.3-1 cm, green to cream-colored, on stipe ca. (0.5-)1-3 cm. Tepals fully connate, forming a cupulate perianth. Style obsolete. Ripe frs. white, with green cap.

Wet forests, 0-1150 m; entire Atl. slope, S Pac. slope (Golfo Dulce region), Isla del Coco. Fl. Jan.-Apr., Jun.-Dec. NE Nic. to extreme NW Col. (Grayum & Burton 4344; CR, MO)

The fully connate tepals of Spathiphyllum laeve, yielding an entire perianth cup, are unique among CR spp. This condition may be difficult to appreciate on some fruiting specimens, since the perianth tears as the fr. enlarges. Otherwise, S. laeve is quite similar in appearance to S. fulvovirens and, especially, S. silvicola, with both of which it occurs sympatrically. For further discussion, see under those entries.

Spathiphyllum montanum (R. A. Baker) Grayum, Phytologia 82: 50. 1997. S. wendlandii subsp. montanum R. A. Baker, in R. A. Baker & W. C. Burger, Phytologia 33: 450. 1976.

Petioles 22.5-52(-80) cm, sheathed ca. (3/8-)3/5-4/5 to leaf-base. Leaf-blades ca. 22-35(-53) × 8.5-16(-25) cm, elliptical to lance-oblong or lance-ovate, cuneate (to subtruncate) at base, with ca. 12-25(-28) primary lateral veins per side. Peduncles ca. 15.5-61.5(-119) cm. Spathe ca. 12-22(-25) × 4-6(-8.7) cm, elliptical to narrowly ovate or obovate, white with green midrib (or completely green?) at anthesis (later becoming green), decurrent on peduncle ca. (2.5-)3.9-7.8. Spadix at anthesis ca. 2.4-4.5(-10) × 0.7-1.2(-1.8) cm, whitish (pistils) or green (perianth), subsessile or on stipe to ca. 0.7(-1.2) cm. Tepals distinct. Style conical-exserted, ca. 0.5-2.5(-4.5) mm long. Ripe frs. white.

Wet forests, 1100-2000 m; Atl. slope and near Continental Divide, Cords. Tilarán and Central, and Talamanca, Pac. slope Cord. Talamanca, Cerro Azahar, Cerro Turrubares. Fl. Jan., Mar.-Jun., Aug.-Dec. CR and W Pan. (Liesner et al. 15584; CR, MO)

This sp., at least in its typical form, is recognized by its cloud-forest habitat, smallish size, and bright white flowering spathes. It is the only CR Spathiphyllum sp. that has been collected above 1300 m elevation, and also our smallest (on average) sp. with broad, erect, decurrent spathes. Some populations on the Atl. slope of the Cord. Talamanca S from the vicinity of Moravia de Chirripó (e.g., Fernández 824, INB) comprise mostly much larger plants in every respect, and account for all of the parenthetical extremes in the above description. This material differs in certain other details (e.g., in possibly having spathes green at anthesis), and may prove to merit taxonomic recognition.

Spathiphyllum phryniifolium Schott, Oesterr. Bot. Wochenbl. 7: 159. 1857. S. floribundum sensu Fl. Panama, non (Linden & André) N. E. Br.; S. zetekianum Standl.

Petioles ca. 16.5-95 cm, sheathed ca. 2/5-15/16 to leaf-base. Leaf-blades ca. 20-47.5 × (2-)5.5-22.5 cm, lanceolate (sometimes narrowly so) or narrowly elliptical to ovate, cuneate to rounded or truncate at base, with ca. 12-24 primary lateral veins per side. Peduncles ca. 35-105 cm. Spathe ca. 8-27(-34.5) × 2.7-8.5(-11.5) cm, narrowly to broadly elliptical to lance-ovate or oblanceolate, bright green at anthesis, decurrent on peduncle ca. 3.2-8.2 cm. Spadix at anthesis ca. (2-)3.3-9.5 × (0.5-)0.8-1.8 cm, green or cream-yellowish, subsessile or on stipe to ca. 2 cm. Tepals distinct. Style conical-exserted, ca. 1.5-2.5 mm long. Ripe frs. apparently green.

Wet and moist forests, 0-1100 m; entire Atl. slope, Pac. slope Cord. Guanacaste and S from vic. Barranca. Fl. Jan., May-Aug. Bel. (and possibly northward) to E Pan. (Solomon 19100; INB, MO)

This is one of just two CR Spathiphyllum spp. with broad, erect, long-decurrent spathes that occurs in the understory of primary forest at low (below 1100 m) elevations (the other being the very different S. wendlandii). It is also the only sp. in this group with green flowering spathes and exserted styles (but see the discussion under S. montanum). It may be confused with S. atrovirens (green spathes, but obsolete styles) or, at its upper elevational limits, with S. montanum; however, S. phryniifolium has been collected above 600 m only in the Cord. Guanacaste, where S. montanum has not been found.

Although widespread in CR, S. phryniifolium is nowhere common. Furthermore, the plants may be inconspicuous, even at anthesis, due to the greenish coloration of the spathes. This sp. has frequently lanceolate leaf-blades, with comparatively long-acuminate apices.

Spathiphyllum silvicola R. A. Baker, in R. A. Baker & W. C. Burger, Phytologia 33: 448. 1976.

Petioles ca. 13-76 cm, sheathed ca. 1/3-3/5 to leaf-base. Leaf-blades 15-38.5 × 4.5-11.5(-15.3) cm, narrowly elliptical or lance-oblong, cuneate to (rarely) rounded at base, with ca. (9-)12-23 primary lateral veins per side. Peduncles ca. 35-96 cm. Spathe ca. 7.9-14.5 × 1.7-4.3 cm, lanceolate or narrowly elliptical to lance-oblong or -ovate, light green or white with greenish veins at anthesis, decurrent on peduncle 0.4-1.4 cm. Spadix at anthesis ca. 3.6-7.5 × 0.4-0.8 cm, white (becoming yellowish or green), on stipe ca. 0.4-1.6 cm. Tepals connate in basal half, separate distally. Style obsolete. Ripe frs. white, with yellow cap.

Wet forests, 0-500+ m; Pac. slope S from RB Carara. Fl. Feb., May-Sep., Nov. ENDEMIC. (Grayum et al. 7548; CR, MO)

This is the only Spathiphyllum sp. in the Pac. lowlands of CR with a narrow, reflexed, scarcely decurrent spathe and distally separate tepals. It is otherwise extremely similar to the partially sympatric S. laeve, which has fully connate tepals. The Atl. slope S. fulvovirens also bears a resemblance (see key, couplet 3). Spathiphyllum silvicola is a common and frequently collected sp.

Spathiphyllum wendlandii Schott, Oesterr. Bot. Z. 8: 179. 1858.

Petioles ca. 25-61 cm, sheathed to geniculum. Leaf-blades ca. 38-74 × 11-28 cm, narrowly or broadly elliptical to lance-oblong or oblanceolate, ± attenuate at base (where sometimes decurrent on the geniculum), with ca. 19-42 primary lateral veins per side. Peduncles ca. 42-87 cm. Spathe ca. 16-29 × 5.5-9.8 cm, narrowly to broadly elliptical, white (with green midrib), decurrent on peduncle ca. 3.2-8 cm. Spadix at anthesis ca. 3.5-11.5 × 1.2-1.6 cm, white (pistils), on stipe ca. 0.4-1.8 cm. Tepals distinct. Style conical-exserted, stout to slender, 0.75-2.5 mm long. Color of ripe frs. unknown.

Wet forests, 0-1150 m; Atl. slope Cord. Central (to vic. Tortuguero) and Cord. Talamanca, Pac. slope S from R.B. Carara. Fl. Feb.-Jul., Sep., Oct. CR and Pan. (Liesner 2895; CR, MO)

Spathiphyllum wendlandii is distinctive, among CR spp., in its fully sheathed petioles, exceptionally numerous primary lateral leaf veins, and broad, bright white flowering spathes. On the other hand, Pac. slope populations differ consistently from those on the Atl. slope in having shorter, proportionately thicker spadices, subentire (as opposed to fimbriate) tepals, and thicker, shorter styles. Furthermore, S. wendlandii tends to occur in primary forest on the Pac. slope, rather than in secondary forest as on the Atl. slope. This Pac. material may prove to warrant taxonomic recognition.

Spathiphyllum wendlandii has been collected from above 650 m elevation only in the Pac. Fila CosteÒa.

Stenospermation

Pérez de Gómez, A. 1983. A revision of Stenospermation (Araceae) in Central America. Unpubl. M. S. thesis, Saint Louis Univ., St. Louis, MO, U. S. A.

Ca. 60 spp., Guat. to Bol. and Guiana; 7 spp. in CR.

Epiphytes on trunks or branches; stems terete, spreading to suberect, rarely (elsewhere) appressed-climbing; plants lacking milky sap. Leaves spiraled. Petioles never peltately attached, with a geniculum. Leaf-blades simple, narrowly lanceolate to broadly elliptical, ± coriaceous, with primary veins usually obscure, the margins entire. Infls. solitary in leaf (or cataphyll) axils, the peduncles usually cernuous distally; spathe erect and enveloping spadix at anthesis, white to cream, without a proximal tube, becoming broadly splayed and promptly deciduous; spadix uniform, lacking sterile fls. toward base. Fls. bisexual, naked; stamens 4, distinct; style thickened, shorter than ovary; stigma linear-oblong; ovary 2-locular; ovules 4+ per locule, borne basally. Frs. white to orangish, several- to many-seeded. Seeds 2-2.5 mm long, fusiform to claviform.

Its deciduous spathes and naked, bisexual fls. immediately place Stenospermation in tribe Monstereae, together with Heteropsis, Monstera, and Rhodospatha. Among these genera, Stenospermation is easily recognized by its comparatively short-stemmed, usually epiphytic habit, spirally arranged leaves, and thickish leaf-blades with obscure venation. It is further distinctive in its usually distally cernuous (at anthesis) peduncles and numerous, small, ± obovoid seeds.

1 Petiole sheath horizontally splayed ("winged"), extending to leaf-base; spadix ca. 1.8 cm, stipitate by ca. 0.4 cm; 1190 m, Atl. slope S Cord. Talamanca (Alto Urén)...S. pteropus

1' Petiole sheath erect to involute, often ending before leaf-base (at least on some larger leaves); spadix > 5 cm or, if shorter, sessile or stipitate by 0.2 cm or less; widespread.

2 Spadix (1.2-)1.7-5.4 cm, sessile or stipitate by up to 0.2 cm.

3 Internodes becoming relatively elongate, to 5+ × 0.8(-1) cm; petioles becoming distant, the sheaths remaining ± uniformly herbaceous; spadix ca. 0.25-0.5 cm wide, uniformly thickened; ripe frs. white; 0-1300 m...S. angustifolium

3' Internodes relatively stout, to ca. 1.5(-2) × 2 cm; petioles usually overlapping at base, the sheaths becoming brittle-scarious on margins; spadix ca. 0.5-0.9 cm wide, ± clavate (especially toward fr.); ripe frs. cream-yellowish to yellow-orange; 600-1800 m...S. sessile

2' Spadix (3-)4.3-18.8 cm, stipitate by 0.3-2.2 cm.

4 Petioles (2-)3.1-9.6(-17.5?) cm; peduncles (3-)7.3-12.5(-16.5?) cm; 0-900 m...S. marantifolium

4' Petioles 7.5-29.1(-43.5) cm; peduncles 13-58 cm; ca. 500-2100 m.

5 Leaf-blades 2.1-5.8(-9.7) cm wide; peduncles 13-27 cm; spadix (3.8-)5.9-9.0 cm; ca. 850-2100 m...S. spruceanum

5' Leaf-blades 5.3-13 cm wide; peduncles 23-58 cm; spadix 7-18.8 cm; ca. 500-2000 m.

6 Leaf-blades 18-42 × 6.2-17 cm, drying reddish brown; spadix 10.7-19 × 1-1.4 cm, the floriferous portion decurrent on stipe; 500-1200(-1500?) m...S. majus

6' Leaf-blades 15-28.5 × 5.3-9.6 cm, drying blackish; spadix 7-13.5 × 0.6-1 cm, the floriferous portion non-decurrent on stipe; ca. 1450-2000 m...S. robustum

Stenospermation angustifolium Hemsl., Biol. cent.-amer., Bot. 3: 425. 1885.

Epiphyte to at least 30 m above the ground (though often much lower). Petioles ca. 1.6-13.5 cm, sheathed ca. 3/10-100% to leaf-base. Leaf-blades ca. 4.5-23.7 × 1.2-5.6 cm, lance-ovate (rarely), lanceolate, or narrowly elliptical to lance-oblong or oblanceolate. Peduncles ca. 5-19.5 cm. Spathe white. Spadix (1.2-)1.7-3.8 × 0.25-0.5 cm, white to grayish or greenish, sessile or stipitate by up to 0.2 cm. Ripe frs. white.

Wet forests, 0-1300 m; entire Atl. slope, Pac. slope S from R.B. Carara. Fl. Jan.-Dec. NE Nic. to Pac. Ecua., N Col. (Río Magdalena Valley). (Gómez et al. 20533; CR, MO)

This is the most frequently collected CR Stenospermation sp. below 1000 m elevation. It is distinguished by its smallish size, slender, elongate stems, and small, subsessile infls. The only spp. in our area with which it might be confused are S. pteropus and S. sessile (see under those entries for further discussion). The rather different S. marantifolium is the only other congener occurring below 500 m elevation in CR.

Specimens of S. angustifolium from the Pac. slope tend to have somewhat larger leaf-blades than Atl. material.

Stenospermation majus Grayum, Phytologia 82: 50. 1997.

Epiphytes on stumps, trunks, or occasionally in canopy (or on downfalls). Petioles 14-22.5(-43.5) cm, sheathed ca. 2/3-ca. 100% to leaf-base. Leaf-blades ca. 18-42 × 6.2-17 cm, elliptical. Peduncles ca. 23-39 cm. Spathe pale green. Spadix ca. 10.7-19 × 1-1.4 cm, cream-colored, stipitate by ca. 0.5-2.2 cm. Color of ripe frs. unknown.

Wet forests, ca. 500-1200 m; Atl. slope Cords. Tilarán, Central, and Talamanca. Fl. Feb.-Apr., Jun., Jul. ENDEMIC? (Haber & Zuchowski 11153; INB, MO)

Stenospermation majus is readily recognized by its comparatively massive size (S. robustum, despite the name, is smaller), foliage drying reddish brown, and elongate spadices with some basal fls. decurrent along the spadix. This sp. is restricted to relatively inaccessible portions of the Atl. slope, hence is infrequently collected.

Stenospermation marantifolium Hemsl., Biol. cent.-amer., Bot. 3: 425. 1885.

Trunk epiphytes ca. 2-3 m above the ground or in canopy (occasionally on shrubs or rocks). Petioles ca. (2-)3.1-9.6(-17.5?) cm, sheathed (1/2?-) 3/5-ca. 100% to leaf-base. Leaf-blades ca. 9-34 × (2.8-)4.5-11 cm, elliptical to lance-oblong, oblanceolate, or obovate. Peduncles ca. (3-)7.3-12.5(-16.5?) cm. Spathe white or light green. Spadix (2.5-)4.3-7.9 × 0.7-1.1 cm, white, stipitate by (0.3-)0.5-1.3 cm. Ripe frs. white.

Wet forests, 0-900 m; entire Atl. slope, S Pac. slope (vic. Golfito and Osa Pen.). Fl. Jan.-Jul., Sep., Oct. S cent. Nic. to E cent. Pan. (Hammel & Flores 17081; CR, MO)

Stenospermation marantifolium is distinguished by its stipitate spadix, comparatively short petioles and peduncles, and lowland habitat. This is the only CR Stenospermation with a conspicuously stipitate spadix found below 500 m elevation. Croat & Hannon 79283 (MO), Hammel et al. 18400 (INB, MO), Fco. Quesada 193 (INB), and J. F. Morales 3569 (NB) are the only collections of any Stenospermation other than S. angustifolium from the Pac. lowlands of CR. Though tentatively referred to S. marantifolium, they diverge somewhat from Atl. slope material of that sp. in having longer and less extensively sheathed petioles, as well as longer peduncles and shorter stipes. It is possible that two different taxa are involved.

Stenospermation pteropus Grayum, Phytologia 82: 52. 1997.

Epiphyte. Petioles ca. 1.9-3.5 cm, sheathed to leaf-base. Leaf-blades 5.5-8.3 × 1.2-1.8 cm, lanceolate or narrowly elliptical. Peduncles ca. 4 cm. Color of spathe unknown. Spadix ca. 1.8 × 0.4 cm, of unknown color, stipitate by ca. 0.4 cm. Color of ripe frs. unknown.

Wet forests, 1150-1200 m; Atl. slope Cord. Talamanca near Pan. border. Fl. Jul. ENDEMIC. (Herrera 3353; CR, MO, USJ)

Stenospermation pteropus is known only from the type collection, from ca. 1190 m elevation in the Río Urén basin. This, the smallest CR Stenospermation, is most similar to S. angustifolium, from which it differs in its horizontally splayed petiole sheaths and longer infl. stipe.

Stenospermation robustum Engl., Bot. Jahrb. Syst. 37: 113. 1905.

Terrestrial or epiphytic. Petioles 7.5-23 cm, sheathed 2/5-9/10 to leaf-base. Leaf-blades ca. 15-28.5 × 5.3-9.6 cm, narrowly or ± broadly elliptical to lance-oblong or oblanceolate. Peduncles 24-58 cm. Spathe cream-white (within) to yellow. Spadix 7-13.5 × 0.6-1 cm, white to yellowish orange or brownish, stipitate by 0.5-1.5 cm. Ripe frs. pale yellow, orange at summit.

Wet forests, ca. 1450-2000 m; Atl. slope and near Continental Divide, Cord. Central (Volcán Barva, La Palma). Fl. [??]. Guat., CR to Col. (Cord. Occidental). (Tonduz 12525, CR)

Pérez de Gómez (1983; in herb.) has consistently applied the name Stenospermation robustum to a distinctive entity, well-collected in Pan., but not matched by any CR material I have seen. On the other hand, I have not seen the Costa Rican type, nor any of the other three Costa Rican specimens cited by her. The above description is abstracted from Pérez de Gómez (1983) and supplemented by Pan. material annotated by her. I rather suspect that the name may be misapplied (see discussion under S. spruceanum).

Stenospermation sessile Engl., Bot. Jahrb. Syst. 37: 111. 1905.

Terrestrial or epiphytic on roots or trunks, to at least 18 m above ground, the stems to at least 1 m. Petioles ca. 6-33.2 cm, sheathed ca. 1/2-100% to leaf-base. Leaf-blades ca. 6.2-26 × 2.3-7.6(-9.7) cm, ± narrowly elliptical or lance-oblong to oblanceolate or narrowly obovate. Peduncles ca. 8.8-36.5 cm. Spathe white to light green. Spadix ca. 2-5.4 × 0.5-0.9 cm, ± clavate, white or cream-yellowish to green, sessile or stipitate to ca. 0.1 cm. Ripe frs. cream-yellowish to yellow-orange (darker at summit).

Wet forests, ca. 600-1800 m; Atl. slope and near Continental Divide, Cords. Tilarán and Central, N Cord. Talamanca (Río Reventazón basin), Pac. slope Cerro Azahar, Montes del Aguacate. Fl. Jan., Feb., Apr.-Dec. CR to E cent. Pan. (Grayum et al. 8082; CR, MO)

This is the most frequently collected CR Stenospermation sp. above 1000 m elevation. It is confused only with S. angustifolium, our only other sp. with sessile or subsessile spadices. Generally speaking, S. sessile comprises more robust plants with shorter, thicker internodes, longer petioles, and larger leaf-blades; however, some material (especially from the Cord. Tilarán) simulates S. angustifolium in stem width, petiole length, and leaf-blade size. See the key (couplet 3) for further distinguishing features.

Stenospermation spruceanum Schott, Gen. aroid. t. 70. 1858.

Trunk epiphytes from ca. 2-3 m above the ground, up to the canopy (occasionally on logs, etc.). Petioles ca. 7.7-29.1 cm, sheathed (2/5-)1/2-100% to leaf-base. Leaf-blades ca. 12-34.5 × 2.1-5.8(-9.7) cm, ± narrowly lanceolate, lance-oblong, or elliptical. Peduncles ca. 13-27 cm. Spathe whitish or greenish. Spadix (3.8-)5.9-9 × 0.6-1.1 cm, white or greenish, stipitate by 0.3-1.5 cm. Ripe frs. apparently white.

Wet forests, ca. 850-2100 m; Atl. slope Cords. Tilarán, Central, and Talamanca. Fl. Feb.-Apr., Jul., Sep., Nov. Guat. to Per˙, Guianas, Braz. (Herrera 5187; INB, MO)

This sp. is characterized by its rather long petioles, usually narrow leaf-blades, typically pendent peduncles, short, stipitate spadices, and montane habitat. The overall geographic range, as given above, is from Pérez de Gómez (1983), who interpreted this sp. in a very broad sense. The name S. spruceanum, based on a collection from the Amaz. lowlands of Braz., is almost certainly misapplied to Cent. Amer. material. The CR entity appears to range no further S than W Pan.; it is conceivable that the name S. robustum will prove to be the correct name for our material.

Several collections (e.g., Herrera 240, CR, MO) from above 1800 m elevation on Volcán Barva have unusually large and broad leaf-blades.

Syngonium

Croat, T. B. 1982. A revision of Syngonium (Araceae). Ann. Missouri Bot. Gard. 68: 565-651.

Ca. 36 spp., throughout the New World trops. (but centered in CR and Pan.).; 16 spp. in CR.

Vining herbs, appressed-climbing hemiepiphytes, or canopy vines; milky sap present. Leaves spiraled. Petioles never peltately attached, lacking a geniculum. Leaf-blades simple or trifoliolate to pedately compound, when simple lanceolate to ovate-cordate, sagittate or hastate, very rarely pinnately lobed (elsewhere). Infls. 1-many per axil; spathe with proximal tube and distal lamina, the latter usually abscising after anthesis; spadix with separate male and female regions, with medial sterile zone but lacking distal sterile appendage. Fls. unisexual, naked; male fls. with 3 or 4 stamens connate in synandria; sterile male fls. with ± elongate synandrodia; female fls. connate, without conspicuous styles; stigma convex, scarcely lobed; ovary (1)2(3)-locular; ovules 1(2) per locule, basal or at center of axile placentae. Infr. a syncarp of connate, 1(2)-seeded berries.

The combination of a scandent, epiphytic habit and milky sap in most organs is virtually unique to Syngonium, among those aroid genera represented in CR (but see also Philodendron cretosum). A few spp. of Syngonium have clear or orangish sap, at least in the stem and petioles (e.g., S. rayi, S. standleyanum). In all cases, the connate pistils and syncarpous frs. are diagnostic. Several spp. of Philodendron with tripartite or trifoliolate leaf-blades are routinely confused with Syngonium (see under the former genus).

The common name Mano de tigre is applied to several of our spp. with pedately compound leaf-blades, especially S. macrophyllum.

Syngonium auritum (L.) Schott, of Gr. Ant., is occasionally cult. for ornament in CR; it is distinguished by its trisect to 5-foliolate leaf-blades and spathe-blade ca. twice as the staminate spadix region. Several native spp. are also frequently cult. as ornamentals, especially S. hoffmannii, S. podophyllum, and S. wendlandii.

1 Leaf-blades of adult plants simple, auriculate to cordate, sagittate, or hastate at base.

2 Petioles > 25 cm; leaf-blades mostly > 31 cm long and > 12 cm wide; peduncles > 8.5 cm.

3 Petioles ca. 28-50 cm; leaf-blades 29-48 × 12.5-22.5 cm; spathe tube uniformly greenish externally and within; spadix ca. 8.5-7 × 1.4-1.5 cm, abruptly narrowed below fertile male region; Pac. slope...S. hastiferum

3' Petioles mostly > 50 cm; leaf-blades mostly > 48 cm long and > 23 cm wide; spathe tube reddish to purplish within (and often externally as well); spadix ca. 10.3-17.8 × 1.3-2.4 cm, abruptly narrowed below sterile male region; Atl. slope...S. schottianum

2' Petioles < 25 cm; leaf-blades < 31 cm long or < 12 cm wide; peduncles < 8.5 cm.

4 Leaf-blades > 3× longer than wide, minutely auriculate at base (auricles < 5 mm long); spadix at anthesis < 4 cm; Osa Pen....S. castroi

4' Leaf-blades (at least, most larger ones) < 3× longer than wide, cordate or auriculate to sagittately or hastately lobed at base (auricles or lobes > 5 mm long, at least on some larger leaves); spadix at anthesis > 4 cm; widespread.

5 Petioles and young stems glaucous; young stems, undersides of young leaf-blades, and main veins (below) on older leaf-blades reddish or purplish; leaf-blades coriaceous, weakly glossy above, the margins plane; primary lateral veins strongly ascending (< 45∞), mostly arising from lower half of midrib; spadix ca. 1-1.1 cm wide; Atl. slope...S. armigerum

5' Petioles, leaf-blades, and young stems neither glaucous nor reddened; leaf-blades membranous, dark green and satiny or velvety above, paler below, the margins finely crispate-undulate; primary lateral veins ascending at ca. 45∞, well distributed along midrib; spadix ca. 0.5-0.7 cm wide [CHECK S. oduberi!!!]; both slopes.

6 Leaf-blades ≥ 2× as long as petioles and > 10× as long as basal lobes; S Pac. slope (Osa Pen. and S Fila CosteÒa)...S. oduberi

6' Leaf-blades < 2× as long as petioles and < 10× as long as basal lobes; both slopes (absent from Pen. Osa)...S. rayi

1' Leaf-blades of adult plants compound or virtually so, deeply trisect to trifoliolate or pedately 5-11-foliolate.

7 Leaf-blades pedately 5-11-foliolate.

8 Medial leaflet with 9-16 primary lateral veins per side; infls. 1-4 per axil; spathe tube reddish or purplish within at anthesis; spadix at anthesis 7.8-12 cm, longer than peduncle, abruptly narrowed below sterile male region; pollen coarsely knobby; ripe syncarp white...S. triphyllum

8' Medial leaflet with ca. 2-9 primary lateral veins per side; infls. 1-9 per axil; spathe tube uniformly greenish within at anthesis; spadix at anthesis 4.3-8.1 cm, shorter than peduncle, abruptly narrowed below fertile male region; pollen spiny; ripe syncarp brownish.

9 Leaf-blades 5-11-foliolate; petiole with acute, median, adaxial keel beyond sheath; juvenile leaf-blades usually marked with whitish or grayish along veins; male fls. apically retuse, toothlike, the individual stamens not demarcated; 50-300(-700) m, moist forests of Prov. Guanacaste and Zona Norte...S. angustatum

9' Leaf-blades 5-7(-9)-foliolate; petiole subterete to adaxially flattened or obtusely keeled beyond sheath; juvenile leaf-blades plain green; male fls. truncate at apex, the individual stamens ± clearly demarcated; widespread, but absent from Guanacaste lowlands...[Proceed to couplet 12.]

7' Leaf-blades deeply trisect to trifoliolate, the lateral leaflets often sagittately to hastately lobed basiscopically, but lobes never pinched off so as to resemble separate leaflets.

10 Infls. 1-9 per axil; spathe tube at anthesis uniformly greenish within; spadix at anthesis 4.3-8.1 cm, usually shorter than peduncle, abruptly narrowed at base of fertile male region; pollen spiny (unknown in S. hastiferum).

11 Leaf-blades simple (deeply trisect or trilobate), with lateral lobes < 2/3 length of medial lobe; medial lobe ca. 29-48 × 12.5-22.5 cm, with ca. 9-15 primary lateral veins per side; juvenile leaf-blades ± narrowly elliptical to lance-ovate, shallowly cordate at base; Pac. slope...S. hastiferum

11' Leaf-blades fully compound, with lateral leaflets > 2/3 length of medial leaflet; medial leaflet ca. 9.2-36.5 × 3.5-18 cm, with ca. 4-9 primary lateral veins per side; juvenile leaf-blades ovate-cordate or becoming sagittately to hastately lobed; widespread.

12 Stems not glaucous, ± densely covered with elongate, brownish projections ca. 0.1-0.6 mm long; peduncle not glaucous; external surface of spathe tube not glaucous, becoming whitish to yellowish in fr.; 0-650(-1150) m, Atl. slope...S. peliocladum

12' Stems (at least when young) glaucous, smooth to verrucose-roughened (but without elongate projections); peduncle usually glaucous; external surface of spathe tube usually glaucous, greenish in fr., or becoming orange-yellow to bright red; widespread.

13 Canopy lianas (typically), in primary forest; petiole sheath on larger leaves often ending < halfway to leaf-base, with free distal portion ca. 0.5-4.7 cm; leaf-blades ± coriaceous, drying reddish brown, (3-)5-7(-9) foliolate; medial leaflet 20-36.5 × (5.3-)6.9-18 cm; spathe tube greenish externally in fr.; spadix ca. 6.1-7.3 × 1-1.4 cm; juvenile leaf-blades ovate-cordate...S. macrophyllum

13' Understory vines, often in secondary forest; petiole sheath extending > halfway to fl.-base, with free distal portion < 0.6 cm; leaf-blades thinly coriaceous, usually drying green, 3-5-foliolate; medial leaflet 9.2-29(-36) × 3.5-13.4(-16.2) cm; spathe tube becoming orange-yellow to bright red externally in fr.; spadix ca. 5.1-6.7 × 0.7-1 cm; juvenile leaf-blades quickly becoming sagittately to hastately lobed...S. podophyllum

10' Infls. 1-4 per axil; spathe tube at anthesis reddish or purplish within; spadix at anthesis ca. (4.8-)6.7-13.6 cm, usually longer than peduncle, abruptly narrowed at base of sterile male region; pollen smooth or coarsely knobby.

14 Plants glaucous on young petioles, peduncles, young stems, and/or external surface of spathe tube; foliage usually drying reddish brown.

15 Medial leaflets with 3-8 conspicuous primary lateral veins per side, diverging from midrib at < 60∞; both slopes, but not < 1100 m on Pac. slope...S. hoffmannii

15' Medial leaflets with 6-10 indistinct primary lateral veins per side, diverging from midrib at ca. 60-90∞; 50-600 m, S Pac. slope (Osa Pen.)...S. laterinervium

14' Plants not glaucous on any parts; foliage usually drying green or blackish (reddish brown in S. hoffmannii).

16 Medial leaflets with ca. 8-17 primary lateral veins per side; spadix ca. 7.8-13.6 cm; pollen coarsely knobby; juvenile leaf-blades plain green.

17 Petiole sheath frequently extending to within 1 cm of blade; sap of stems and petioles clear, tardily oxidizing to rust-orange; leaf-blades pale green above, drying green, the lateral leaflets < 70% length of medial leaflet; spadix 8.8-13.6 × 1-1.3 cm; mostly secondary forest, 50-700+ m, N Atl. slope...S. standleyanum

17' Petiole sheath never extending to within < 3 cm of blade (on larger leaves); sap of stems and petioles white to yellowish; leaf-blades dark green above, usually drying blackish, the lateral leaflets > 70% length of medial leaflet; spadix 7.8-12 × 0.8-1 cm; mostly primary forest, 0-1000 m, both slopes...S. triphyllum

16' Medial leaflets with ca. 3-11 primary lateral veins per side; spadix ca. 4.8-11.1 cm; pollen smooth; juvenile leaf-blades often marked with whitish or grayish.

18 Leaf-blades usually drying reddish brown; medial leaflet ca. 11.9-27 cm; peduncles ca. 2.5-12 cm; spadix ca. 0.9-1.5 cm wide; juvenile leaf-blades usually plain green, sometimes marked with whitish or grayish; frequently collected plants, both slopes, but not < 1100 m on Pac. slope...S. hoffmannii

18' Leaf-blades usually drying green; medial leaflet ca. (6.9-)7-21.6 cm; peduncles ca. 2.5-8.5 cm; spadix ca. 0.5-1.2 cm wide; juvenile leaf-blades always marked with whitish or grayish; rarely collected plants, 0-1000 m, Pac. slope.

19 Stems smooth; leaf-blades matte to weakly glossy above (not velvety), concolorous to weakly bicolorous; medial leaflet (2.2-)3.6-11 cm wide, with ca. 7-11 primary lateral veins per side; spadix ca. 6.9-11.1 × 0.5-1.2 cm; 500 m, Valle de El General...S. mauroanum

19' Stems finely asperulous-striate, with minute papillae (most evident on younger stems); leaf-blades velvety above, ± bicolorous (dark green above); medial leaflet ca. 1.4-8.3 cm wide, with ca. 3-9 primary lateral veins per side; spadix ca. 6.7-7.3 × 0.5-0.7 cm; 0-1000 m, W Valle Central to coast...S. wendlandii

Syngonium angustatum Schott, Oesterr. Bot. Z. 8: 178. 1858.

Scandent epiphytes, the older stems becoming verruculate-roughened. Petioles ca. 12-37 cm, sheathed for ca. 50-80% total length, with median adaxial keel beyond sheath. Leaf-blades pedately 5-11-foliolate; medial leaflet 11.5-26 × 3.2-9.3 cm, with ca. 2-6 primary lateral veins per side. Infls. ca. 2-8 per axil. Peduncles ca. 7-13 cm. Spathe tube uniformly greenish on both surfaces, often glaucous externally, becoming red or red-orange in fr.; lamina cream-colored. Spadix ca. 4.7-7.3 × 0.7-1.1 cm, the male portion white or cream-yellowish. Ripe syncarp brown.

Moist forests, 50-300(-700) m; N Pac. slope (Cord. Guanacaste to Llanura de Los Guatusos), N Pac. slope (Prov. Guanacaste). Fl. Jan., Jul.-Sep. Mex. (Ver., Chis.) to CR. (Liesner 4658, MO)

This is the only CR Syngonium sp. that regularly has 7-11-foliolate leaf-blades. The habitat of S. angustatum is also distinctive: it is the only Syngonium, and one of few aroid spp., found in the drier portions of the country.

The juvenile leaf-blades of S. angustatum are marked with white along the veins.

Syngonium armigerum (Standl. & L. O. Williams) Croat, Ann. Missouri Bot Gard. 68: 585. 1981. Philodendron armigerum Standl. & L. O. Williams, Ceiba 3: 107. 1952.

Scandent epiphytes on stumps, trunks, or boughs, fertile to at least 2.5 m above the ground. Young stems glaucous, reddish tinged. Petioles ca. 3.5-11.5 cm, glaucous, ± longitudinally striate, sheathed for ca. 95-100% total length. Leaf-blades simple, 8-22 × 2.7-9.8 cm, ± narrowly elliptical to lanceolate, lance-ovate, or lance-deltate, cordate (juvenile) or auriculate to sagittately or hastately lobed at base, reddish to purplish abaxially (at least when young), with ca. 4-6 ± strongly ascending primary lateral veins per side. Infls. 1 or 2 per axil. Peduncles ca. 4-5 cm. Spathe coloration not described. Spadix ca. 9 × 1.1 cm, color not described. Ripe syncarps unknown.

Rain forests, ca. 500-1300 m; Atl. slope Cords. Central and Talamanca. Fl. Jun.. ENDEMIC. (Hammel & Chavarría 17068; CR, MO)

Syngonium armigerum is distinctive by virtue of its simple leaf-blades with strongly ascending primary lateral veins, glaucous young stems and petioles, and, especially, by the reddish to purplish coloration of the young stems and abaxial leaf surface. It is extremely similar to the Pan. S. erythrophyllum Birdsey ex G. S. Bunting, which differs principally in having trifoliolate adult leaf-blades. The juvenile leaf-blades of S. erythrophyllum are essentially indistinguishable from adult foliage of S. armigerum; a tentative report of S. erythrophyllum from CR, based on "juvenile" plants seen in the Reventazón Valley (see Croat, 1981: 612), certainly pertains to S. armigerum.

Syngonium armigerum is a rare sp. of very wet and often remote forests. It is known from just five collections, of which only the one cited above is at anthesis.

Syngonium castroi Grayum, Phytologia 82: 52. 1997.

[Appressed-climbing] epiphytes. Petioles ca. [9-]20-21 cm, sheathed for ca. 75[-100]% total length, the cross-sectional shape not described. Leaf-blades simple, 17.6-32.9 × [4.9-]5-7.4[-8.6] cm, lanceolate to lance-elliptic [or oblanceolate], cuneate [or rounded] to the minutely auriculate base (auricles to ca. 4.5 × 3.5 mm, directed ± backward), with ca. [2-]8 or 9 primary lateral veins per side. Infls. 3 per axil. Peduncles to at least 6.3 cm. Spathe "blanca". Spadix ca. 3.8 × 0.9 cm, "amarillo". Ripe syncarps unknown.

Wet forests, [150-]600 m; [head of Golfo Dulce], Osa Pen.. Fl. Jan. ENDEMIC. (Castro 242, USJ)

Syngonium castroi, definitely known from just the unicate type collection, is an inadequately known sp. It is, nonetheless, distinctive in its narrow, ± falcate leaf-blades virtually unlobed (minutely auriculate) at the base, and very short flowering spadices. Compare with S. oduberi, the only other sp. in the Golfo Dulce region with which it might be confused.

All bracketed information in the above description derives from a sterile collection (Croat & Grayum 59733, MO) of somewhat dubious identity.

Syngonium hastiferum (Standl. & L. O. Williams) Croat, Ann. Missouri Bot. Gard. 68: 595. 1981. Philodendron hastiferum Standl. & L. O. Williams, Ceiba 1: 232. 1951.

Appressed-climbing trunk epiphytes, fertile ca. 3-5 m above the ground. Petioles ca. 28-50 cm, sheathed for ca. 50-90% total length, subterete to adaxially flattened or obtusely keeled beyond sheath. Leaf-blades simple, 29-48 × 12.5-22.5 cm, lance-ovate to elliptical, rarely deeply trisect to trilobate (in which case the foregoing measurements apply only to the medial lobe), sagittately to subhastately lobed at base, with ca. 9-15 primary lateral veins per side (on main, or medial, lobe); tripartite leaf-blades with lateral lobes truncate to auriculate at base. Infls. 3-9 per axil. Peduncles ca. 11-20 cm. Spathe tube uniformly green externally and within; lamina cream-colored. Spadix ca. 6.5-7 × 1.4-1.5 cm, the male portion cream-colored. Ripe syncarp brownish.

Wet forests, 0-700 m; Pac. slope S from San Isidro de El General/Dominical transect. Fl. Jul. ENDEMIC? (dubiously identified sterile collection from E Pan.). (Grayum et al. 4012; CR, MO)

This is the only Syngonium sp. with large, simple leaf-blades on the Pac. slope of CR. It is also our only sp. with (typically) simple leaf-blades that has the inner surface of the spathe tube uniformly greenish. The spathe-tube coloration and other infl. details place S. hastiferum in the S. podophyllum sp. group, despite its unusual leaf-blade morphology.

Croat & Grayum 59798 (MO), from the Osa Pen., is highly distinct in having deeply trisect to trifoliolate leaf-blades, with prominent, hastately spreading basal lobes. Though conceivably representing an undescribed sp., this collection differs in no other way from S. hastiferum, to which it is here referred. Similar variation in leaf-blade morphology is documented for S. chiapense Matuda, a closely related Mexican sp.

Syngonium hoffmannii Schott, Oesterr. Bot. Z. 8: 178. 1858. S. glaucopetiolatum Croat; S. stenophyllum Birdsey, nom. ined.

Scandent epiphytes, fertile to at least 12 m above the ground. Young stems glaucous or not. Petioles ca. 11-38 cm, sheathed for ca. 70-90(-95)% total length, glaucous or not, with median adaxial keel beyond sheath. Leaf-blades trifoliolate; medial leaflet (9.8-)11.9-27 × (2.1-)2.9-9.5 cm, with ca. 3-8 primary lateral veins per side; lateral leaflets cuneate or truncate to auriculate or sagittately to hastately lobed at base. Infls. 1 or 2(3) per axil. Peduncles ca. (2.3-)2.5-12 cm, sometimes glaucous. Spathe tube deep reddish or purplish within, green (sometimes glaucous) externally; lamina cream-white to -yellow. Spadix ca. 4.8-10.5 × (0.7-)0.9-1.5 cm, the male portion white. Ripe syncarp sordid.

Wet forests, 0-1800 m; Atl. slope and near Continental Divide, all main cords. (to R.N.F.S. Barra del Colorado), Cerros de La Carpintera, Pac. slope (above 1100 m) Cord. Talamanca, Cerros de Escaz˙. Fl. Jan., Feb., Apr.-Nov. CR to E Pan. (Grayum & Badilla 10274; INB, MO)

Syngonium hoffmannii is a rather nondescript sp., characterized by its frequently (though not invariably) glaucous parts, adaxially keeled petioles, consistently trifoliolate leaf-blades with 3-8 primary lateral veins per side on the medial leaflet, few (usually 1 or 2) infls. per axil, and reddish or purplish inner spathe-tube surface. This is by far our commonest Syngonium sp. above 1000 m elevation. It is most apt to be confused with S. triphyllum (not found > 1000 m), which is never glaucous and has usually 9-16 primary lateral veins per side on the medial leaflet, but also resembles the allopatric S. mauroanum and S. wendlandii (see key, couplet 18) and, especially, S. laterinervium (see key, couplet 15).

Material from below 1000 m elevation on the Atl. slope here assigned to S. hoffmannii comprises generally less robust plants, with somewhat smaller leaf-blades and more slender spadices (e.g., Grayum 6829, CR, MO). Furthermore, these low-elevation populations appear relatively infertile; though common in the forest at E.B. La Selva, S. hoffmannii has never been observed to flower naturally there. A rare fertile lowland collection of S. hoffmannii served as the "type" of the never-published Syngonium stenophyllum.

Syngonium hoffmannii is frequently planted as an ornamental in CR, especially on the Valle Central. The juvenile leaf-blades are sometimes marked with silvery gray.

Syngonium laterinervium Croat, Ann. Missouri Bot. Gard. 68: 620. 1981.

Scandent epiphytes, fertile to at least 15 m above the ground. Young stems glaucous. Petioles ca. 8.8-22 cm, sheathed for ca. 75-95% total length, with median adaxial keel beyond sheath. Leaf-blades trifoliolate; medial leaflet ca. 8.5-22.6 × 2.3-7.6 cm, with ca. 6-10 ± indistinct, widely spreading primary lateral veins per side; lateral leaflets truncate to auriculate or (rarely) ± sagittately lobed at base. Infls. 1 or 2 (3) per axil. Peduncles ca. 2.5-4.8 cm, ± glaucous. Spathe tube deep red or purplish within, yellow-green to pinkish red externally; lamina white to pale pink. Spadix ca. 6.7-9 × 0.8-0.9 cm, the male portion white. Ripe syncarp cream-yellowish.

Wet forests, 50-600 m; S Pac. slope (Osa Pen.). Fl. Mar., May-Jul, Oct. CR and extreme W Pan. (Punta Burica). (Grayum et al. 4110; CR, MO)

This is the only Syngonium sp. on the Osa Pen. with glaucous foliage and consistently trifoliolate leaf-blades. It is very similar to the allopatric S. hoffmannii (not found < 1100 m on the Pac. slope), from which it differs principally in leaf venation characteristics (see key, couplet 15). Syngonium laterinervium is common within its limited range.

Syngonium macrophyllum Engl., in Engl. & K. Krause, Pflanzenr. IV.23E (Heft 71): 128. 1920.

Scandent epiphytes, fertile to at least 4 m above the ground (and probably much higher). Petioles ca. (17-)25-64 cm, sheathed for ca. 35-80% total length, subterete or ± flattened adaxially beyond sheath. Leaf-blades pedately (3-)5-7(-9) foliolate; medial leaflet ca. (15-)20-36.5 × (5.3-)6.9-18 cm, with ca. 6-9 primary lateral veins per side. Infls. (1?-)3-9 per axil. Peduncles ca. 7-17 cm, sometimes glaucous. Spathe tube greenish within, pale green and sometimes glaucous externally; lamina white. Spadix ca. 6.1-7.3 × 1-1.4 cm, the male portion white. Ripe syncarp brownish.

Wet forests, 0-750+ m; entire Atl. slope, S Pac. slope (Osa Pen.). Fl. Jun., Aug., Oct. S Mex. (Chis., Tab.) to Pac. Ecua. (Croat 36339; CR, MO)

Syngonium macrophyllum is a member of the S. podophyllum complex (see under the latter sp.). It is distinguished by its coarse habit, glaucous parts, ovate-cordate juvenile leaf-blades, comparatively short petiole sheaths usually with a prolonged distal free portion, large, thickish, reddish-brown-drying leaf-blades, and large spadices (see key, couplet 13). Large specimens are easily identified; however, smaller ones may be very difficult to distinguish from S. podophyllum, from which this sp. may not be separable.

Syngonium mauroanum Birdsey ex G. S. Bunting, Baileya 14: 19. 1966.

Terrestrial, epilithic, or appressed-climbing on trunks, fertile to at least 3 m above the ground. Petioles ca. (6.6-)12-32.5 cm, sheathed for ca. 56-80% total length, with median adaxial keel beyond sheath. Leaf-blades trifoliolate (perhaps rarely pedately 5-foliolate); medial leaflet (6.9-)9-21 × (2.2-)3.6-11 cm, with ca. 7-11 primary lateral veins per side; lateral leaflets broadly cuneate or truncate to sagittately or hastately lobed at base. Infls. 1 or 2 per axil. Peduncles ca. 3.5-8.5 cm. Spathe tube deep reddish or purplish within, greenish externally; lamina white. Spadix 6.9-11.9 × 0.5-1.2 cm, the male portion white. Color of ripe syncarps unknown.

Moist forests, 500 m; S Pac. slope (Ujarrás de Buenos Aires). Fl. May, Jun. (Pan.). CR and W Pan. (Grayum 10230; INB, MO)

Syngonium mauroanum may be recognized, in CR, by its trifoliolate leaf-blades and moist forest habitat in the Valle de El General. It is scarcely distinct from S. wendlandii (see key, couplet 19), which occurs in the same habitats but is allopatric. Though known from just one site in CR, S. mauroanum is widespread and frequently collected in W Pan.

The juvenile leaf-blades of this sp. are marked with silver-gray.

Syngonium oduberi T. Ray, Aroideana 3: 128. 1980.

Scandent epiphytes, fertile to at least 2.5 m above the ground. Petioles ca. 5.2-11.2 cm, sheathed for ca. 75-95% total length, flattened with medial rib adaxially beyond sheath. Leaf-blades simple, ca. 14.4-23.5 × 3.5-9.1 cm, ± narrowly elliptical to oblanceolate, auriculate to subhastately lobed at base, ± satiny adaxially, with ca. 10-12 primary lateral veins per side. Infls. solitary. Peduncles ca. 3.6-5.9 cm. Spathe tube (in fr.) wine-red within, green externally; color of lamina unknown. Spadix [dimensions???], the male portion greenish or grayish. Ripe syncarp white.

Wet forests, 0-900 m; S Pac. slope (Osa Pen., S Fila CosteÒa). Fl. Oct.-Dec. ENDEMIC. (Knapp 2190, MO)

Syngonium oduberi is distinctive in its simple leaf-blades on relatively short petioles (< half the length of the blade). The leaf-blades are, furthermore, of a peculiar, elongate shape, with very small basal lobes. Compare especially the allopatric S. rayi (key, couplet 6) and the less similar, though sympatric, S. castroi.

Syngonium peliocladum Schott, Prodr. syst. Aroid. 202. 1860. S. podophyllum var. peliocladum (Schott) Croat.

Scandent epiphytes, fertile to at least 4 m above the ground. Stems not glaucous, ± densely covered with elongate projections ca. 0.1-0.6 mm. Petioles ca. 16.6-34.5 cm, sheathed for ca. 56-90% total length, sometimes glaucous at base, subterete (or faintly ribbed adaxially) beyond sheath. Leaf-blades trifoliolate or pedately 5-foliolate; medial leaflet 12-26 × 4.5-12 cm, with ca. 4-9 primary lateral veins per side; lateral leaflets auriculate to sagittately or hastately lobed (the lobes sometimes free, i.e., the leaf-blades 5-foliolate). Infls. ca. 4-8 per axil. Peduncles ca. 6.5-18.5 cm. Spathe tube green within, green externally (may be glaucous when young), becoming whitish or yellowish in fr.; lamina white. Spadix ca. 4.3-8.1 × 0.7-1.5 cm, the male portion white to cream-yellowish. Ripe syncarp brownish.

Wet forests, 0-650(-1150) m; Atl. slope Cords. Central (to P.N. Tortuguero) and Talamanca. Fl. Jan., Jun.-Sep., Nov., Dec. CR and W Pan. (Prov. Bocas del Toro). (Robles 2847; CR, MO)

The elongate projections densely covering the stems of S. peliocladum immediately distinguish it from any other CR Syngonium. Otherwise, it is quite similar to the widespread S. podophyllum, of which it was considered a variety by Croat (1981). The latter sp. also differs from S. peliocladum in its often glaucous young stems and usually externally bright orange to reddish (as opposed to whitish or yellowish) fruiting spathes. In my opinion, S. peliocladum is more distinctive than S. macrophyllum within the S. podophyllum complex.

Syngonium podophyllum Schott, Bot. Zeitung (Berlin) 9: 85. 1851.

Scandent epiphytes, fertile to at least 6 m above the ground, the stems often ± verruculate. Young stems sometimes glaucous. Petioles ca. (10.3-)17.9-47.5(-51.5) cm, sheathed for ca. 56-90% total length, sometimes glaucous, subterete to bluntly or sharply keeled adaxially beyond sheath. Leaf-blades trifoliolate to pedately 5-foliolate; medial leaflet ca. 9.2-29(-36) × 3.5-13.4(-16.2) cm, with ca. 4-9 primary lateral veins per side; lateral leaflets truncate or auriculate to sagittately or hastately lobed at base (the lobes sometimes free, i.e., the leaf-blades 5-foliolate). Infls. 1-8 per axil. Peduncles ca. 5-17 cm, sometimes glaucous. Spathe tube green or greenish white within, green (and sometimes glaucous) externally, becoming orange-yellow to bright red in fr.; lamina white. Spadix ca. 5.1-6.7 × 0.7-1 cm, the male portion white. Ripe syncarp dark brownish.

Wet and moist forests, 0-1100(-1600) m; entire Atl. slope, Pac. slope Cords. Guanacaste and Tilarán and S from R.B. Carara. Fl. Jan., Feb., Apr.-Jun., Aug.-Oct. Mex. (Nay., Tamaul.) to Bol., Guianas, Trin., Braz., Gr. Ant., Bahamas, SE USA. (Grayum et al. 5813; CR, MO)

The Syngonium podophyllum sp. group, within CR, is distinguished by petioles usually terete or subterete beyond the sheath, frequently pedately compound leaf-blades, numerous (1-8+) infls. per axil, relatively long (compared with the spadices) peduncles, spadices abruptly constricted below the fertile (rather than sterile) male region (with the sterile male region the narrower than the fertile male region), spiny pollen, and brownish syncarps. In CR, this group comprises S. angustatum, S. macrophyllum, S. peliocladum, S. podophyllum, and the anomalous (in having usually simple leaf-blades) S. hastiferum. For distinctions from S. podophyllum, the most widespread and variable sp. in the group, see other the other spp. (especially S. macrophyllum, the most similar to S. podophyllum).

Though widespread in the CR lowlands, S. podophyllum is apparently absent from sites harboring S. peliocladum (such as E.B. La Selva).

Syngonium podophyllum is widely grown as an ornamental, in CR and throughout the world, with many gaudily marked cultivars known.

Syngonium rayi Croat & Grayum, in Grayum, Phytologia 82: 53. 1997.

Scandent epiphytes, fertile ca. 2-3 m above the ground. Petioles ca. (3.6-)8.4-22.5 cm, sheathed for ca. 58-86(-96)% total length, the cross-sectional shape not described. Leaf-blades simple, ca. (5.6-)10-24 × (2.5-)3.5-13 cm, ovate, oblong-ovate or oblong-deltate to elliptical, lance-oblong, or lanceolate, cordate to sagittate or hastate at base, dark green to purplish and matte to velvety adaxially, with ca. (3)4-11 primary lateral veins per side. Infls. 1-4 per axil. Peduncles ca. 2.2-5.2 cm. Spathe tube dark wine-red within, green externally; lamina cream-white. Spadix ca. 8.1-9.4 × 0.5-0.7 cm, the male portion white. Ripe syncarps unknown.

Wet forests, 0-900(-1500) m; Atl. slope Cords. Guanacaste, Tilarán and Central (to R.N.F.S. Barra del Colorado), Pac. slope Cord. Guanacaste (> 900 m) and Fila CosteÒa (Cerro Nara and Cerro Pito). Fl. May-Jul., Dec. CR and E Pan. (Cerro Jefe, Comarca de San Blas). (Hammel et al. 15263, MO)

Syngonium rayi is characterized by its smallish, simple leaf-blades, dark green and velvety adaxially. These features are shared with the allopatric S. oduberi, which has relatively longer (compared with the petioles), differently shaped leaf-blades (see key, couplet 6). The sap of S. rayi is clear, unlike that of most Syngonium spp., which is milky (sap color of S. oduberi is unknown).

Mature individuals of Syngonium rayi are rare; this sp. has been collected in fl. only about a dozen times, and all but one of these collections are unicates. At E.B. La Selva, where S. rayi is best known, it has never been observed in fr. (presumably due to the great rarity of flowering individuals). Nonetheless, juvenile plants believed to represent this sp. (e.g., Lee s. n. 4/8/1984, MO-3304465) are abundant along forest trails, suggesting that vegetative multiplication may be involved.

This sp., as presently circumscribed, is rather a variable one. Populations from the Cord. Guanacaste and from C. Nara and C. Pito, in the Pac. Fila CosteÒa, differ widely in leaf-blade shape and size from one another, and also from Atl. lowland populations in the Sarapiquí region.

Syngonium schottianum H. Wendl. ex Schott, Prodr. syst. Aroid. 199. 1860. Porphyrospatha schottiana (H. Wendl. ex Schott) Engl.

Appressed-climbing trunk epiphytes, usually fertile ca. 6-10 m above the ground. Petioles (47-)55-117 cm, sheathed for ca. 70-90% total length, subterete beyond sheath. Leaf-blades simple, ca. (42.5-)46.5-100 × 22-48 cm, ovate or deltate to lance-ovate, deeply sagittate to hastate at base, matte and ± glaucous abaxially, with ca. 9-17 primary lateral veins per side. Infls. to at least 4 per axil. Peduncles ca. 8.5-24.5 cm. Spathe tube reddish to purplish within, green to red or purplish externally; lamina white. Spadix ca. 10.3-17.8 × 1.3-2.4 cm, white. Ripe syncarp apparently white.

Wet forests, 0-1200 m; entire Atl. slope. Fl. Jan., Feb., Apr., May, Aug., Sep., Nov. Hond. to W Pan. (Robles 2130; CR, MO)

Syngonium schottianum is instantly identified by virtue of its very large size, simple leaf-blades, and Atl. slope habitat. Our only other remotely similar Syngonium is the Pac. S. hastiferum, which has smaller leaf-blades and very different infls. Plants of S. schottianum tend to be rather high-growing and difficult of access. From a distance, they are easily mistaken for a Philodendron sp. (the copious milky sap of S. schottianum sets it apart). Up close, S. schottianum resembles nothing so much as an epiphytic ×anthosoma (of which none exists).

This sp. is very abundant at E.B. La Selva.

Syngonium standleyanum G. S. Bunting, Baileya 14: 21. 1966.

Scandent epiphytes, fertile to at least 5 m above the ground. Stems not glaucous. Petioles ca. (15.5-)17-32.5 cm, sheathed for ca. 80-95% total length, with median adaxial keel beyond sheath. Leaf-blades trifoliolate; medial leaflet ca. 13-27.5 × 7-15.5 cm, with ca. 8-17 primary lateral veins per side; lateral leaflets cuneate to rounded or auriculate at base. Infls. 1-4(5) per axil. Peduncles ca. 4-10 cm. Spathe tube green red within, externally; lamina white. Spadix ca. 8.8-13.6 × 1-1.3 cm, the male portion white. Ripe syncarp unknown.

Wet forests, 50-700+ m; Atl. slope Cords. Guanacaste, Tilarán and Central. Fl. Jan., Jun.-Aug. SE Nic. and CR. (Hammel & Trainer 13206, MO)

This is the only CR Syngonium sp. with trifoliolate leaf-blades in which the lateral leaflets are regularly < 70% the length of the medial leaflet (with the exception of one aberrant collection of S. hastiferum, which see). Otherwise, the little-known S. standleyanum is scarcely distinct from the much more widespread and better known S. triphyllum (though the former name is older). In addition to non-glaucous parts and trifoliolate leaf-blades with 8-17 primary lateral veins per side on the medial leaflet, these two spp. share the distinctive, coarsely knobby pollen type otherwise unknown in the genus. At E.B. La Selva, where S. standleyanum is best known, the two spp. appear to be separated by habitat and phenology, in addition to the morphological characters noted in the key (couplet 17).

Syngonium triphyllum Birdsey ex Croat, Ann. Missouri Bot. Gard. 68: 642. 1981.

Appressed-climbing trunk epiphytes, fertile ca. 2-4 m above the ground. Stems not glaucous. Petioles ca. 17.5-46.5 cm, sheathed for ca. 70-90% total length, with median adaxial keel beyond sheath. Leaf-blades trifoliolate to pedately 5-foliolate; medial leaflet 17-32 × 6.1-12.5 cm, with ca. (7-)9-16 primary lateral veins per side; lateral leaflets cuneate to truncate, auriculate, or sagittately to hastately lobed at base (the lobes sometimes free, i.e., the leaf-blades 5-foliolate). Infls. ca. 1-4+ per axil. Peduncles ca. 3.8-14 cm. Spathe tube reddish or purplish within, green (or tinged reddish) externally, becoming bright red on both sides in fr.; lamina white or sordid. Spadix 7.8-12 × 0.8-1 cm, the male portion white or sordid. Ripe syncarp white.

Wet forests, 0-1000 m; entire Atl. slope, Pac. slope S from R.B. Carara. Fl. Jan., Oct., Nov. Hond. to W Pan. (Grayum et al. 4445; CR, MO)

Syngonium triphyllum, widespread in CR lowland forests, is distinguished by its non-glaucous parts, adaxially keeled petioles, compound, blackish drying leaf-blades with 9-16 pairs of primary lateral veins on the medial leaflet, few (1-4+) infls., reddish inner spathe-tube coloration, peculiar, coarsely knobby pollen, bright red fruiting spathes, and pure white syncarps. It is most similar and no doubt most closely related to the rare S. standleyanum (see key, couplet 17). Trifoliolate specimens should also be compared with S. hoffmannii, which has frequently glaucous parts and fewer primary lateral veins on the medial leaflet.

Despite the sp. epithet, plants of S. triphyllum frequently develop 5-foliolate leaf-blades.

Syngonium wendlandii Schott, Oesterr. Bot. Z. 8: 178. 1858. Garrobo.

Scandent epiphytes on shrubs or trunks, fertile ca. 0.5-4 m above the ground. Stems becoming brownish and finely asperulous-striate. Petioles (8-)10.4-37 cm, sheathed for ca. 56-86% total length, finely striate, with median adaxial keel beyond sheath. Leaf-blades trifoliolate, dark green and velvety adaxially; medial leaflet 7-21.6 × 1.4-8.3 cm, with ca. 3-9 primary lateral veins per side; lateral leaflets truncate to auriculate or sagittate to hastate at base. Infls. 1-4 per axil. Peduncles 2.5-6.8 cm, finely striate. Spathe tube deep reddish or purplish within, green externally (and finely striate), becoming yellowish post-anthesis; lamina white or cream. Spadix ca. 6.7-10.3 × 0.5-0.7 cm, the male portion white. Color of ripe syncarps not described.

Moist and wet forests, 0-1000 m; cent. Pac. slope, vic. Barranca to R.B. Carara, to W end of Valle Central (Alajuela, Santa Ana, Z.P. El Rodeo, Atenas) and W slope of Cerro Turrubares. Fl. Mar.-Apr. ENDEMIC. (Grayum & Kress 8570; CR, MO)

Syngonium wendlandii is easily recognized in life by its non-glaucous, finely asperulous-striate stems and trifoliolate leaf-blades, adaxially dark green and velvety. It is most similar to the allopatric S. mauroanum (see key, couplet 19), which has smooth stems and non-velvety leaf-blades, but should also be compared with the allopatric S. hoffmannii.

In addition to its attractive, velvety adult foliage, S. wendlandii has colorfully marked (with silvery gray) juvenile leaf-blades. Because of these features, this sp., restricted naturally to a small portion of cent. Pac. CR, is much more familiar in cult. than in the wild. It is occasionally planted for ornament not only in CR, but around the world.

Urospatha

Engler, A. 1911. Lasioideae. In A. Engler (ed.), Das Pflanzenreich IV.23 (Heft 48): 1-130. Engelmann, Berlin.

Ca. 20 spp., Guat. to Pan., Amaz. Col. to Per˙, Ven., SE Braz.; 1 sp. in CR.

Urospatha grandis Schott, Bonplandia 5: 128. 1857. U. tonduzii Engl.; U. tuerckheimii Engl.

Terrestrial, paludal; stems rhizomatous, horizontal or perpendicular; plants without milky sap. Leaves few, spiraled. Petioles ca. 0.8-1.5 m, not peltately attached, lacking a geniculum, terete, spongy, maroon-mottled toward base. Leaf-blades simple, sagittate to subhastate at base, the margins entire; medial lobe ca. 24-49 × 16-44 cm, with ca. 5-15 primary lateral veins per side; lateral lobes 24-51 × 9-24 cm, with posterior rib naked for ca. 1-3 cm. Infls. solitary in axils; peduncle ca. 0.9-1.75 cm, terete, spongy, often maroon-mottled toward base, recurved distally in fr.; spathe ca. 23-41 × 3-8 cm, erect, light green (usually suffused with maroon) to purplish externally, cream-colored to yellow-green within (with purplish blush at very base), emitting a fruity fragrance at anthesis, the margins barely overlapping at base, the apex attenuate and spirally twisted; spadix uniform, ca. 5.4-9.2 × 0.9-2.3 cm at anthesis, yellow- or olive-green to deep maroon, on stipe ca. 0.8-1.5 cm. Fls. bisexual, with perianth of 4-6 distinct tepals; stamens 4-6, distinct; style absent; stigma convex; ovary incompletely 2-locular; ovules 2-several per locule, borne near center of axile placentae. Frs. 1- or 2-seeded. Seeds ca. 0.8-1.1 cm, ± lunate.

Wet forest, 0-150(-900) m; entire Atl. slope, very rare and local on Pac. slope (Valle Central). Fl. Jan., Mar., May, Sep., Nov. Atl. Guat. to cent. Pan. (J. F. Morales et al. 1641; INB, MO)

This sp. is easily recognized by its subaquatic habitat, subterranean, rhizomatous stems, long petioles and peduncles, bold, sagittate leaf-blades, and attenuate, spirally twisted spathe apex. In terms of infl. morphology, Urospatha most closely resembles Dracontium (among CR aroid genera); however, the two genera are very different vegetatively.

Urospatha grandis is quintessentially a sp. of the Atl. coastal plains, typically found in standing or slow-moving water or other damp sites including marshes, sluggish streams, wet pastures, and river backwaters. It may be locally abundant, sometimes forming virtually pure stands. Croat 36854 (MO) was collected in a swampy area at 900 m elevation near Alajuela, on the Pac. slope.

It is now generally agreed that the holotype illustration of Urospatha friedrichsthalii Schott, a name often applied to this sp. (in herb.), actually depicts a still unidentified Sagittaria sp. (Alismataceae).

Xanthosoma

Engler, A. & K. Krause. 1920. Colocasioideae. In A. Engler (ed.), Das Pflanzenreich IV.23.E (Heft 71): 3-132. Engelmann, Berlin.

Ca. 45 spp., throughout tropical regions of the New World; 6 spp. in CR.

Terrestrial; stems cormose or stout and erect, with copious milky sap. Leaves spiraled. Petioles rarely peltately attached, lacking a geniculum. Leaf-blades simple or trifoliolate to pedately compound, when simple narrowly lanceolate (rarely) to ovate-cordate, sagittate, or hastate. Infls. 1-€ per axil; spathe with proximal tube and distal lamina, the latter usually abscising after anthesis; spadix with separate male and female regions, with medial sterile zone, but lacking distal sterile appendage. Fls. unisexual, naked; male fls. with 4-6 stamens connate in synandria; sterile male fls. with elongate synandrodia; female fls. with thickened, discoid styles coherent with those of adjacent fls.; stigma discoid or convex, 3- or 4-lobed; ovary 2-4-locular; ovules numerous per locule, borne along axile placentae. Frs. whitish, many-seeded.

The combination of a terrestrial habit and copious milky sap is sufficient to distinguish Xanthosoma from the vast majority of CR Araceae. Only Caladium bicolor (with peltate leaves) and the very rare Chlorospatha croatiana (see under Xanthosoma wendlandii) share these basic features. Dieffenbachia spp. may also evince milky sap, particularly in the stems, but differ in leaf-blade morphology and infl. details. Introduced Asian spp. of Alocasia are superficially very similar to some Xanthosoma spp., but have colorless to reddish sap.

This treatment is highly speculative for those Xanthosoma taxa comprising plants with large, simple, cordate to sagittate, glabrous leaf-blades. Herbarium specimens of these are few and usually poorly prepared, with inadequate notes. Moreover, many sp. names have been validated, mostly based on cultivated plants of unknown origin and typified only by illustrations. Because of this situation, some cultivated or ruderal plants may not be identifiable by means of the following key.

1 Leaf-blades pedately compound...X. wendlandii

1' Leaf-blades simple.

2 Foliage (petioles, leaf-blades, peduncles, and exterior spathe surface) ± densely pubescent...X. mexicanum

2' Foliage glabrous.

3 Stem aerial, erect (or decumbent at base), to 1-3 m; plants not glaucous, the leaf-blades ± concolorous; leaf-blades with primary lateral veins convex adaxially, ca. (7-)9-14 per side; spathe tube usually deep red within (and often externally as well); female fls. (stigmas) bright orange; (100-)1000-1800+ m...X. undipes

3' Stem subterranean or, if aerial, < 1 m; plants glaucous (or with leaf-blades whitened below); leaf-blades with primary lateral veins sunken adaxially, ca. 7-10 per side; spathe tube green within and externally (rarely with pinkish blotch or collar at base of spadix); female fls. pale yellow; 0-1350+ m.

4 Posterior ribs of leaf-blades naked for ca. 1-7 cm; stem becoming aerial and erect, to at least 30 cm...X. robustum

4' Posterior ribs of leaf-blades winged with laminar tissue to petiole, or naked for 0.5 cm or less; stem subterranean, or becoming briefly aerial.

5 Leaf-blades markedly bicolored, bright green adaxially, whitened abaxially; plants not otherwise glaucous; spadix ca. 6-10.7 × 0.5-0.7 cm; ripe frs. yellow-orange to bright orange; indigenous plants of Pac. slope, 0-650 m...X. dealbatum

5' Leaf-blades weakly bicolored, ± glaucous abaxially; petioles and peduncles usually glaucous and/or purplish tinged; spadix ca. 14.3-16.3(-22) × 0.7-1.2(-1.6) cm; ripe frs. unknown; cult. and escaped, 0-1350 m...X. sagittifolium

Xanthosoma dealbatum Grayum, Phytologia 82: 55. 1997.

Stem subterranean, a subglobose corm ca. 3 cm diam. Petioles ca. 46-89 cm, sheathed ca. 30-43% total length, terete beyond sheath. Leaf-blades simple, ca. 31-57 × 17.5-32 cm, lance-deltate to ± pandurate, sagittate at base, strongly bicolored (matte and whitened abaxially), with ca. 5-10 adaxially ± sunken primary lateral veins per side; posterior rib naked for 0-0.8 cm. Infls. to at least 4 per axil. Peduncles ca. 18-37 cm. Spathe tube uniformly green within and externally; lamina white to cream-colored. Spadix ca. 6-10.7 × 0.5-0.7 cm, the fertile male portion white; sterile male portion [???]; fertile female portion (stigmas) pale yellow. Ripe frs. yellow-orange to orange (with axis of female portion of spadix somewhat paler).

Wet forests, 0-650 m; Pac. slope S from Río Grande de Tárcoles. Fl. Jun., Jul., Sep., Oct. ENDEMIC. (Grayum et al. 4016; CR, MO)

Xanthosoma dealbatum is distinguished by its cormose habit, sagittate, strongly bicolored leaf-blades, orange frs., and Pac. lowland habitat. It is most similar to the cult. (and escaping) X. sagittifolium (see key, couplet 5). This is a seasonal sp., at least in the N portion of its range, with only the leafless corms surviving the drier times of year.

Xanthosoma mexicanum Liebm., Vidensk. Meddel. Dansk Naturhist. Foren. KjØbenhavn 1849: 15. 1849. X. croatianum L. D. Gómez & Gómez-Laur. (as 'croatana'); X. pilosum K. Koch & Augustin.

Stem subterranean, a subglobose to oblate corm ca. 1.5-3 cm diam. Petioles ca. 14-54 cm, sheathed ca. 46-59% total length, obscurely striate, densely pubescent, subterete beyond sheath. Leaf-blades simple, ca. 13.9-37 × 7.6-31 cm, deltate or ovate to oblong-ovate, cordate to subsagittate at base, pubescent on both surfaces (or glabrescent adaxially), with ca. 4-6 adaxially sunken primary lateral veins per side; posterior rib naked for 0-0.5 cm. Infls. ca. 1-3 per axil. Peduncles ca. 11-33 cm, pubescent. Spathe tube deep purplish within, uniformly green, finely striate, and pubescent externally; lamina mostly white or cream-colored (purplish toward base). Spadix ca. 7.2-14.4 × 0.5-0.8 cm, the fertile male portion white; sterile male portion (narrow part) dark purplish; fertile female portion (stigmas) pale yellow. Ripe frs. whitish.

Wet and moist forests, 0-1200 m; N Atl. slope (very rare; E.B. La Selva), entire Pac. slope. Fl. Jul.-Sep. Mex. (Jal.) to N Col. and W Ven. (Haber 8527; CR, MO)

This sp. is unique among CR Xanthosoma in its pubescent foliage. Only the leafless corms survive the drier periods of the year.

Xanthosoma robustum Schott, Oesterr. Bot. Wochenbl. 3: 370. 1853.

Stem aerial, erect, to at least 30 cm. Petioles to at least 1.5 m, sheathed ca. 50% total length, glaucous, subterete beyond sheath (very low-convex adaxially with obscure medial ridge). Leaf-blades simple, ca. 50-110 × 48-100 cm, ± deltate, subsagittate at base (the basal lobes ± quadrate), ± glaucous or whitish abaxially, with ca. 7-9 adaxially sunken primary lateral veins per side; posterior rib naked for ca. 1-7 cm. Infls. to at least 5 per axil. Peduncles ca. 11-35 cm. Spathe tube uniformly light greenish within, green and glaucous externally; lamina white to cream-colored. Spadix ca. 20-24 × 1-1.5 cm, the fertile male portion white to cream; sterile male portion white or pinkish; fertile female portion (stigmas) [???]. Ripe frs. [???].

Wet forests, 50-200+ m; both slopes, rare or seldom collected (E.B. La Selva, Osa Pen.). Mex. (N. L., Tam.) to CR. (A. Chacón 1079, INB)

Xanthosoma robustum is characterized by its erect, aerial stems, glaucous foliage, naked posterior leaf ribs, and uniformly greenish inner spathe tube surface. The infls. are the largest of any CR Xanthosoma sp. This sp. is most similar to X. undipes (with non-glaucous foliage and usually red spathe tubes) and X. sagittifolium (acaulescent and usually with winged posterior ribs). Indeed, the plants treated here as X. robustum may prove to represent merely robust individuals of X. sagittifolium.

Xanthosoma robustum is seldom collected in CR, and may be strictly adventive. It is known mainly from disturbed, often wet sites.

Xanthosoma sagittifolium (L.) Schott, in Schott & Endl., Melet. bot. 19. 1832. Arum sagittifolium L., Sp. pl. 966. 1753; X. atrovirens K. Koch & C. D. Bouché; X. mafaffa Schott; X. nigrum Stellfeld; X. roseum Schott; X. violaceum Schott; X. xanthorrhizon (Jacq.) K. Koch. Tiquisque.

Stem subterranean or briefly aerial, subglobose, to at least 2.5 cm diam. Petioles ca. 29-90(-125) cm, sheathed ca. 35-60% total length, sometimes tinged purplish, terete beyond sheath. Leaf-blades simple, ca. 37-61(-100+) × 25-48(-96) cm, ± deltate, sagittate at base, ± glaucous or whitened abaxially, with ca. 5-8 adaxially sunken primary lateral veins per side; posterior rib naked for 0-0.5 cm. Infls. 1-13 per axil. Peduncles ca. 10.5-30(-44) cm, ± compressed. Spathe tube greenish within (occasionally with pinkish blotch at base of spadix) and externally; lamina cream-colored (sometimes with pinkish suffusion and/or veining). Spadix ca. 14.3-16.3(-22) × 0.7-1.2(-1.6) cm, the fertile male portion white or pale pinkish; sterile male portion pink; fertile female portion (stigmas) pale yellowish. Ripe frs. unknown.

Wet and moist forests, cult. and escaped, 0-1350 m; both slopes. Fl. Feb., Sep.-Nov. Natural range unknown. (Grayum et al. 8818; CR, MO)

Xanthosoma sagittifolium is characterized by its cormose habit, glaucous and often purplish-tinged foliage, sagittate leaf-blades with the posterior ribs winged to near the petiole, and uniformly green spathe tubes. It is most similar to X. dealbatum (see key, couplet 5) and X. robustum (with aerial stems).

This is a very familiar sp. in CR. Its edible corms (tiquisque) are widely available in the marketplace, and the plants are often seen as patio ornamentals, as on the Valle Central. They also occur as adventives in pastures and along roadsides, especially in the Atl. lowlands.

Because the taxonomy and nomenclature of the cult. Xanthosoma are in such chaos, a single, variable sp. is here recognized, and the oldest available name is applied. Various cultivars are represented in CR, e.g., tiquisque blanco and tiquisque colorado. Some names may prove to be incorrecly synonymized here, such as Xanthosoma roseum, typified by a Costa Rican collection.

Xanthosoma undipes (K. Koch & C. D. Bouché) K. Koch, Bonplandia 4: 3. 1856. Alocasia undipes K. Koch & C. D. Bouché, in A. Braun et al., Append. gen. sp. Hort. berol. 1854 5. 1854-1855; X. jacquinii Schott, nom. illeg.; X. roseum sensu Standl. (1937), non Schott.

Stem aerial, to 1-3 m long and 10-15 cm diam., often ± decumbent at base. Petioles ca. 30-140 cm, sheathed ca. 30-80% total length, subterete beyond sheath (or ± flattened adaxially with low, medial ridge distally). Leaf-blades simple, ca. (35-)46-80+ × 37-90 cm, ± deltate, deeply cordate or subsagittate at base (the basal lobes ± quadrate), weakly glossy to glossy below (not glaucous), with ca. (7-)9-14 adaxially convex primary lateral veins per side; posterior rib naked for ca. (1.5-)2-7 cm. Infls. to at least 5-7 per axil. Peduncles ca. 8.5-34 cm. Spathe tube uniformly greenish white or (most frequently) reddish to purplish within (at least basally), uniformly green to partly or ± uniformly deep red or purplish externally; lamina white or cream-colored to greenish white. Spadix ca. 9.5-18.4 × 0.9-1.7 cm, the fertile male portion white or cream-colored; sterile male portion white to cream-yellowish; fertile female portion (stigmas) bright orange. Ripe frs. pale greenish yellow.

Wet forests, (100-)1000-1800+ m; Atl. slope and near Continental Divide, all major cords., Pac. slope Cord. Talamanca, Cerro Azahar, Fila CosteÒa, Osa Pen.. Fl. Jan.-Mar., May-Dec. CR to Ecua., Ven. (Grayum 10374; INB, MO)

This is our largest and most conspicuous indigenous Xanthosoma sp., the stout, pachycaulous stems attaining at least 3 m in length. It is also the only simple-leaved CR Xanthosoma sp. with adaxially convex (as opposed to sunken) primary lateral leaf-veins and (except for the pubescent X. mexicanum) our only simple-leaved sp. with the spathe tube reddish within. Unfortunately, stem morphology, leaf-vein disposition, spathe coloration, and most of the other distinctive features of X. undipes (non-glaucous foliage, naked posterior rib on the leaf-blades, bright orange female fls.) are frequently not appreciable on herbarium specimens and not described on the labels.

Xanthosoma undipes is quintessentially a montane sp., most abundant above 1000 m elevation, but descending to below 200 m on the Atl. slope of the Cord. Central (E.B. La Selva) and Osa Pen.. It usually grows near water (along creeks, wet pastures, lagoon edges, etc.).

Xanthosoma wendlandii (Schott) Schott, Oesterr. Bot. Z. 15: 33. 1865. Acontias wendlandii Schott, Oesterr. Bot. Z. 8: 178. 1858; X. hoffmannii (Schott) Schott. Comida de perro.

Stem subterranean, a subglobose or oblate corm ca. 1.5-3 cm diam. Petioles ca. 49-130 cm, sheathed ca. 26-36% total length, finely striate, densely mottled or suffused with purplish, terete beyond sheath. Leaf-blades pedately 5-9-foliolate; medial leaflet ca. 17-50 × 6-17.5 cm, with ca. 4-9 primary lateral veins per side; posterior rib naked for 0-0.5 cm. Infls. 1-[??] per axil. Peduncles ca. 23-37 cm. Spathe tube pale greenish within (sometimes with blotch or collar of purplish at base of spadix), green externally; lamina whitish. Spadix ca. 11-16.5 × 1.1-1.3 cm, the fertile male portion white; sterile male portion [???]; fertile female portion (stigmas) very pale green. Ripe frs. white.

Wet and moist forests, 0-1300 m; Pac. slope S to Puriscal region (Z.P. La Cangreja). Fl. Jun.-Aug. Mex. (Son.) to CR, W Pan. (Pen. Azuero), N Ven. (Grayum et al. 4016; CR, MO)

This is the only CR Xanthosoma sp. with compound leaf-blades. In CR, it can only be confused with Chlorospatha croatiana, which has an erect (non-cormose) rhizome, much more slender infls., and occurs in wetter (mainly Atl. slope) forests. The more similar Xanthosoma helleborifolium (Jacq.) Schott, which has generally more numerous (11-17) leaflets and more slender spadices than X. wendlandii, has been attributed to CR (by Standley, 1937) and N to El Salv., but I have seen no collections from N of cent. Pan. Like other cormose Xanthosoma spp. of the seasonally dry Pac. slope (X. dealbatum, X. mexicanum), X. wendlandii survives the "verano" as leafless corms.

Xanthosoma wendlandii is occasionally cultivated as a patio ornamental in CR, especially in the Valle Central.

It is possible that the Cuban X. cubense (Schott) Schott and/or the Brazilian X. pentaphyllum (Schott) Schott will prove conspecific with X. wendlandii; X. pentaphyllum has nomenclatural priority.

Zantedeschia

Letty, C. 1973. The genus Zantedeschia. Bothalia 11: 5-26.

7 spp., S. Afr.; 1 sp. in CR.

Other spp. of Zantedeschia may occasionally be cult. in CR as garden ornamentals, including Z. albomaculata (Hook.) Baill. (white spathes purplish within at base), Z. elliottiana (W. Watson) Engl. (yellow spathes), and Z. rehmannii Engl. (usually with pink spathes), as well as various cultivars and hybrids.

Zantedeschia aethiopica (L.) Spreng., Syst. veg. 3: 765. 1826. Calla aethiopica L., Sp. pl. 968. 1753; Richardia africana Kunth. Cala, cartucho, calla.

Terrestrial; stem subterranean, a thick, fleshy rhizome; plants without milky sap. Leaves spiraled. Petioles ca. 33-82 cm, spongy, never peltately attached, lacking a geniculum. Leaf-blades simple, ca. 15-40 × 6.8-24.5 cm, oblong-deltate to lance-deltate, sagittate to subhastate at base, with ca. 6-10 primary lateral veins per side Infls. 1 or 2 {CHECK!!!} per axil; spathe ca. 10.5-22.5 × (4.5-)7.5-13.5 cm, with greenish proximal tube and broadly splayed, rotund to elliptical, distally reflexed, pure white lamina; spadix at anthesis ca. 3.9-9.6 cm, with separate male and female regions, without medial sterile zone or distal sterile appendage; male region ca. 0.5-0.6 cm wide, orange- or golden-yellow, the male fls. with 2 or 3 distinct stamens; female fls. interspersed with mushroom-shaped staminodia; style short; stigma convex; ovary 3-locular; ovules 1-4 per locule, basal or on axile placentae. Frs. green, becoming orange in proximal portion, 1-12-seeded.

Wet (oak) forests, 1200-3000 m; near Continental Divide, Cords. Central and Talamanca. Fl. Feb., May. S Afr. (naturalized throughout Neotropics). (Grayum & Stiles 5293; CR, MO)

This is an African sp., ± abundantly naturalized at higher elevations in CR, where it prefers boggy pastures and streamside situations. The plants are easily recognized, even from vehicles speeding along the Carretera Interamericana, by their broad, pure white spathes. Close up, the acaulescent habit, spongy petioles, sagittate leaf-blades, and golden spadix further distinguish Z. aethiopica. The plants may superficially resemble some Xanthosoma spp., but lack milky sap.

Zantedeschia aethiopica is also planted intentionally in CR, as a patio ornamental. The cut infls. are sold for arrangements.

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