BFNA Title: Neckera
Author: I. Sastre-de Jesús 
Date: September 6, 2008
Edit Level: R
Version: 1

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden

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XX. NECKERA Hedwig, Sp. Musc. Frond., 200. 1801


Plants medium-sized to robust, light to dark green, sometimes yellowish, mostly shiny, complanate, shelf-forming, primary stem creeping and parallel, secondary stem perpendicular to pendent, unbranched to irregularly branched to pinnate; branches sometimes becoming attenuate. Paraphyllia present or absent, scarce to abundant, filamentose to foliose. Pseudoparaphyllia filamentose to foliose. Primary stem leaves erect to erect-spreading; triangular, lanceolate, broadly ovate to obovate, acute, narrowly acute or sometimes forming a long acumen; margins entire to slightly serrate, recurved to plane at base; costa absent or present, short and double to single; distal medial cells fusiform to linear, basal cells mostly rectangular, alar cells undifferentiated to differentiated, short-quadrate. Secondary stem and branch leaves erect, erect-spreading to spreading; smooth to strongly undulate; ovate to obovate, oblong to oblong-ligulate, oblong-lanceolate, slightly concave or flat, sometimes secund; obtuse, broadly acute, acute to narrowly acute; margins entire to serrate, recurved to plane at base; costa short and double to sometimes single; apical cells rhombic, rhomboidal to fusiform, distal medial cells fusiform to linear; basal cells linear to rectangular, pitted or unpitted, alar cells mostly shortly-quadrate. Sexual condition autoicous or dioicous. Inner perichaetial leaves oblong, oblong-lanceolate to ovate-subulate, abruptly to gradually acute; margins entire to slightly serrate at apex; costa absent or present, reaching mid-leaf; distal medial cells fusiform to linear, pitted or unpitted. Seta short or long, 2--12 mm. Capsule immersed to long-exserted, erect, cylindric, oblong to globose; exostome teeth lanceolate, smooth to densely papillose, somewhat cross-striate at base, sometimes perforate; endostome rudimentary or well developed, with a low to high basal membrane, segments narrow-lanceolate, keeled, smooth to densely papillose, sometimes perforate. Spores papillose, 12--39 \um.


The genus Neckera is defined by asymmetric and dimorphic leaves; that is, central versus lateral leaves. The central leaves are inserted dorsally or ventrally and the costa is almost aligned with the central axis of the stem; while in lateral leaves the insertion line surrounds the stem’s side and thus costa alignment is displaced toward one side. Lateral leaves can be distinguished as dorsal or ventral; for example, if the leaf is mostly inserted dorsally (with costa on the dorsal side) then there will be a small fold on the ventral side.


Species 73 (5 in the flora): North America, Mexico, West Indies (Dominican Republic), Central America, South America, Europe, Asia, Pacific Islands, Australia.


SELECTED REFERENCES: Crum, H. 1983. Mosses of the Great Lakes Forest. 3rd ed.  Ann Arbor, MichiganCrum, H. A. and L. E. Anderson. 1981. Mosses of Eastern North America. 2 vols. New York. He, Si 1997. A revision of Homalia (Musci: Neckeraceae). J. Hattori Bot. Lab. 81: 1--52. Ireland, R. R. 1961. Additions to the moss flora of Shenandoah National Park, Virginia. Bryologist 64: 66--70. Lawton, E. 1971. Moss flora of the Pacific Northwest. Nichinan, Miyasaki, Japan. Norris, D. H. and J. R. Shevock. 2004. Contributions toward a bryoflora of California: 1. A specimen-based catalogue of mosses. Madroño 52: 1--131. Redfearn, P. L., Jr. 1983. Mosses of the Interior Highlands of North America. Reprinted with Changes and Additions. Ann. Missouri Bot. Gard. 59: 1--104. Steere, W. C. 1941. Neckeradelphus, a new genus in the Neckeraceae. Bryologist 44: 147--153. Steere, W. C. 1967. Metaneckera, nomen novum for Neckeradelphus Steere. Bryologist 67: 343--344. Wagner, K. A. 1952. Notes on the Neckeraceae. I. New names and new species. Bryologist 55: 143--147.


1. Plants with mostly smooth leaves.

2. Plants large, 3.5--4 cm; central stem leaves oblong, leaf apex rounded, apiculate  . . . 4. Neckera complanata

2. Plants small, to 2 cm; central stem leaves ovate, leaf apex obtuse to broadly acute  . . . 5. Neckera besseri

1. Plants with mostly undulate leaves

2. Plants with capsules exserted; leaf apices serrate to dentate with recurved teeth. . . 3. Neckera douglasii

2. Plants with capsules immersed to slightly exserted; leaf apices serrulate to entire.

3. Paraphyllia scarce to absent; central stem leaves oblong-ovate, costa short, double or lacking; plants with a broad distribution. . . 1. Neckera pennata

3. Paraphyllia abundant; central stem leaves oblong-ligulate, costa single, reaching 3/4 leaf length; w United States and Canada . . .  2. Neckera menziesii


1. Neckera pennata Hedwig, Sp. Musc. Frond., 200. 1801


Neckera oligocarpa Bruch


Plants 5--11 cm, attenuate branches few or none. Paraphyllia scarce or absent. Stem leaves (central) undulate, oblong-ovate, 2--3(--5) mm, apex acute to broadly acute; margins serrulate at apex, serrulate to entire proximally; costa short, double or absent; apical cells oblong-rhombic, (15--)30--36 x (2--)3--5 \um, distal medial cells oblong-linear, (23--)42--54 x 2--4 \um, basal cells rectangular, 50--60 x 7.5--10 \um, alar cells very few and irregularly short-quadrate. Sexual condition autoicous. Seta ca. 1 mm. Capsule immersed.


Base of trees, trunks, boulders, rock cliffs of conifer and deciduous forests to montane subalpine ecotones; 300--2600 m; Greenland; B.C., N.B., Nfld. and Labr., N.S., N.W.T., Ont., Que., Yukon; Alaska, Ariz., Colo., Conn., Ky., Ill., Ind., Iowa, Maine, Mass., Mich., Minn., Mont., N.H., N.J., N.Mex., N.Y., N.C., Ohio, Oreg., Pa., R.I., S.Dak., Tenn., Tex., Utah, Vt.,  Va., Wash., W.Va., Wis.; Mexico; Europe; Asia; Pacific Islands (New Zealand); Australia.


Neckera pennata is recognized by immersed sporophytes, the undulate, acute to broadly acute leaves, and paraphyllia absent or scarce.


2. Neckera menziesii Drummond, Musci. Amer., Brit. N. Amer. 162. 1828


Metaneckera menziesii (Drummond) Steere, Bryologist 70: 394. 1967


Plants 4--11(--20) cm, regularly pinnate, attenuate branches common. Paraphyllia abundant, lanceolate. Stem leaves (central) concave, undulate, oblong to oblong-ligulate, base slightly auriculate, 3--6 x (1--)2.2--2.5 mm, apex obtuse to broadly acute; margins slightly serrate to serrulate distally, recurved at base; costa single, 3/4 of leaf length; apical cells rhomboidal, (8--)12--18  x 5--6 \um, distal medial cells linear, pitted, 27--36 x 3--5 \um, basal cells quadrate to short-rectangular, 30--54 x 5--6 \um, alar cells quadrate. Sexual condition dioicous. Seta 2--2.5 mm. Capsule immersed.


Logs, trunks, shaded rocks and cliffs, mixed conifer-hardwood, Sequoia, oak, Thuja and Abies forests; 10--1800(--2000) m; Alta., B.C., Yukon; Alaska, Calif., Idaho, Mont., N.Mex., Oreg., S.Dak., Utah, Wash.; Europe; Asia (China, Japan).


Neckera menziesii can be distinguished from other dioicous species by the single costa that extends 3/4 of the leaf length and the slightly serrate margin of straight teeth. In addition, the seta is very short, and the capsule immersed. The presence of abundant paraphyllia and a single costa were used by W. C. Steere (1941, 1967) to segregate this species into the genus Metaneckera. Those characters are common in other Neckera species from South and Central America and Asia and therefore within the limits of the genus. 


3. Neckera douglasii Hooker, Bot. Misc. 1:131, plate 35. 1829


Plants (7--)10--14 (--20) cm, attenuate branches common. Paraphyllia absent. Stem leaves (central) strongly undulate, slightly concave oblong to oblong-lanceolate, base slightly auriculate, 3.5--5 x 1--1.5(--2) mm; apex abruptly acute to acuminate; margins with recurved teeth at apex, entire to slightly serrulate proximally; costa short and double, single or none; apical cells rectangular, (13--)18--30 x 2--2.5 \um, slightly pitted, distal medial cells linear-flexuose, (30--)42--60 x 2 \um, slightly pitted, basal cells fusiform to rectangular (7--)10--12(--15) x  1--2 \um, porose, alar cells irregularly rectangular. Sexual condition dioicous. Seta (2--)4--6 mm. Capsule exserted.


Decaying logs, trunks, hanging from branches, rarely on soil, rocks of mixed conifer-hardwood forests, redwood forest, humid costal forest; 0--500 m; B.C., Alaska, Calif., Idaho, Oreg., Wash.


Neckera douglasii is the only species with large recurved teeth at leaf apex, and it is limited to western North America.


4. Neckera complanata (Hedwig) Huebener, Muscol. Germ., 576. 1833


Leskea complanata Hedwig, Sp. Musc. Frond., 231. 1801


Plants 3.5--4 cm, attenuate flagelliform branches common. Paraphyllia present, rare. Stem leaves (central) smooth, oblong, 2.5--3 x 1.2--1.5 mm; apex rounded-apiculate; apical margin slightly serrulate, entire proximally; costa short and double; apical cells irregularly rhomboidal, 13--18(--24) x 4--6 \um, distal medial cells long-rhomboidal, 24--60 x 4--6 \um, basal cells linear to irregularly rectangular, 5--10 x 1.5 \um, slightly pitted, alar cells oblong to short quadrate. Sexual condition dioicous. Seta 7--12 mm. Capsule exserted.


Trunks, over humus, cliffs, overhanging ledges, shaded vertical sandstone, limestone boulders, wet rocks of mixed forests; (150--)200--500 m; N.B., Nfld. and Labr., N.S., Ont., Ala., Ark., Colo., Ga., Maine, Mass., N.Y., N.C., Penn., Tenn., Va..; Europe; Asia (China).


Neckera complanata is distinguished by the apiculate apex and smooth leaves.


5. Neckera besseri (Lobarzewski) Juratzka, Verh. Zool. Bot. Ges. Wien. 10: 386. 1860


Homalia besseri Lobarzewski, Naturwiss. Abh. (Vienna) 1: 48. 1847


Plants  up to 2 cm or less; flagelliform branches common. Paraphyllia absent. Stem leaves (central)  smooth, ovate to obovate, 1.1--1.3 mm; apex obtuse to broadly acute; margins entire; costa short and double, rarely single; apical cells rhombic, 5--12 x ca. 7 \um, distal medial cells rhombic to rhomboidal, 15--18(--30) x 7--9 \um, basal cells irregularly rectangular, 25--37 x ca. 7 \um, alar cells irregularly quadrate. Sporophyte not reported for the flora area.


Limestone or sandstone cliffs, soil; 300--500 m; Ark., Ky., Mo., N.J., N.Y., Tenn., Vt., Va.; Europe. 


Neckera besseri is distinguished from other Neckera species in the flora by small stature and ovate to obovate stem leaves. Also, it is limited to eastern North America. K. A. Wagner (1952) and R. R. Ireland (1961) treated this species as Homalia jamesii and H. gracilis, respectively, but He (1997) accepted it as Neckera.