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Flora of the Venezuelan Guayana

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ANNONACEAE

11. OXANDRA A. Rich. in Sagra, Hist. Phys. Cuba, Bot. Pl. Vasc. 10: 45. 1845.

by Julian A. Steyermark

Trees or shrubs. Flowers small, axillary, solitary or in few-flowered inflorescences; receptacle hemispheric; pedicels slightly articulate above the base, bearing several small, distichous bracts below the articulation and one above it. Sepals 3, connate at the base, imbricate in bud; petals 6, subequal, rounded, ovate, or oblong, thin, biserially imbricate, the margins often ciliate. Stamens 6--20, flattened; anthers linear, locules not locellate, the connective elongated above the anther locules into a triangular or lanceolate appendage. Carpels few, (1--)4--13; ovule 1, basal, erect. Monocarps shortly stipitate or subsessile, 1-seeded.

Mexico, Guatemala, Panama, West Indies, Colombia, Venezuela, Guyana, Suriname, French Guiana, Ecuador, Peru, Brazil, Bolivia; 24 species, 7 in Venezuela, 6 of these in the flora area.

Key to the Species of Oxandra

1. Base of leaf blades truncate with a laterally directed tooth-like process on each side...O. xylopioides

1. Base of leaf blades acute, obtuse, or slightly rounded, without any tooth-like process...2

2(1). Leaf blades with a distinct marginal vein 3--5 mm from the margin, sec-ondary veins strongly impressed...O. euneura

2. Leaf blades without a distinct marginal vein, secondary veins not impressed...3

3(2). Midrib of upper leaf surface flat

3. Midrib of upper leaf surface distinctly raised...5

4(3). Twigs glabrous; leaves acute to shortly and broadly acuminate at the apex; pedicels 1--2 mm long...O. espintana

4. Twigs covered with erect hairs; leaves long-acuminate at the apex; pedi-cels 3--4 mm long...O. sp. A

5(3). Twigs whitish, glabrous; inflorescence several-flowered; pedicels 5--10 mm long...O. leucodermis

5. Twigs never whitish (brown to black), commonly with brownish hairs when young; inflorescence 1-flowered; pedicels 1--3 mm long...O. asbeckii

Oxandra asbeckii (Pulle) R.E. Fr., Acta Horti Berg. 10: 167. fig. 5a & b. 1931. ---Bocagea asbeckii Pulle, Recueil Trav. Bot. Nierl. 6: 262. 1909.

Shrub or tree 4--15 m; leaves glabrous, shiny on upper surface, lanceolate or elliptic-lanceolate, 7--13 W 2.5--4.5 cm; monocarps ellipsoid, shortly apiculate, 1.5--2 cm long. Evergreen lowland forests, ca. 100 m; Amazonas (Isla del Araguato near Isla Ratsn). Guyana, Suriname, French Guiana.

Oxandra espintana (Spruce ex Benth.) Baill., Hist. Pl. 1: 207. 1868. ---Bocagea espintana Spruce ex Benth., J. Proc. Linn. Soc., Bot. 5: 71. 1860.

Shrub or tree 5--10 m; leaves ovate- or oblong-elliptic, 6--11 W 2--5 cm; monocarps obovoid or ovoid, rounded at apex, ca. 1 cm long. Riparian evergreen forests, ca. 100 m; Bolmvar (middle Rmo Orinoco), Amazonas (Isla Ratsn). Zulia; Colombia, Peru, Brazil, Bolivia. Fig. 382.

Oxandra euneura Diels, Notizbl. Bot. Gart. Berlin-Dahlem 10: 173. 1927.

Tree 2--8 m; leaves 13--20 W 5--7 cm, narrowly elliptic, apex distinctly acuminate; monocarps ellipsoid, strongly narrowed towards the apex, 20--25 W 8--10 mm. Evergreen lowland forests, 100--200 m; Amazonas (Piedra Cocuy). Common in Amazonian Colombia, Peru, and Brazil.

Oxandra leucodermis (Spruce ex Benth.) Warm., Vidensk. Meddel. Dansk Naturhist. Foren. Kjxbenhavn. 1873: 147. 1873. ---Bocagea leucodermis Spruce ex Benth., J. Proc. Linn. Soc., Bot. 5: 71. 1860.

Tree 6--10 m; twigs whitish; leaves oblong-elliptic, 8--17 W 2.5--5 cm; flowers solitary or few on leafless portions of the older stems, pedicels curved; monocarps rounded at apex. Seasonally flooded evergreen lowland forests, ca. 100 m; Amazonas (Rmo Casiquiare, Rmo Negro). Endemic.

Oxandra xylopioides Diels, Notizbl. Bot. Gart. Berlin-Dahlem 10: 172. 1927.

Tree 3--25 m; leaves linear-oblong, 1.5--2 cm wide; flowers small, cream-colored. Evergreen lowland forests, ca. 100--200 m; Amazonas (Rmo Mawarinuma). Amazonian Colombia, Guyana, French Guiana, Ecuador, Peru, Brazil.

Oxandra sp. A. ---Majagua.

Tree 5--6 m; young branches rather densely covered with erect hairs; leaves narrowly ovate, apex long-acuminate, 6--10 W 2--3.5 cm, base obtuse to slightly cordate, both sides reticulate; monocarps subglobose, 8--10 mm diameter. Seasonally flooded forests, ca. 100 m; Amazonas (El Bagre near Puerto Ayacucho).

Scientific Comments:
Paul Berry (peberry@facstaff.wisc.edu) or Kay Yatskievych (kay.yatskievych@mobot.org).

 
 
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