Neckera scabridens Müll.Hal.
Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.
Species Description - Plants medium-sized, mostly soft, in not or scarcely lustrous, pale-green colonies. Primary stems creeping with ca. <1 cm between upright secondary stems, these 3-5 cm tall, complanate-foliate; in cross-section with 3-5 rows of small thick-walled cells surrounding larger firm-walled cells, central strand none; paraphyllia sparse, most concentrated near branch primordia, lanceolate, mostly ca. 0.15 mm long, to 0.28 mm long, 2-3-seriate below, 1-2-seriate above; pseudoparaphyllia broadly foliose, the apex toothed; axillary hairs with (1-)2 short brown basal cells and (2-)3(-4) elongate hyaline distal cells. Primary stem leaves erect, ovate-lanceolate, 1.1-1.7 mm long, gradually acuminate, not undulate, small-cordate at base; margins serrulate to denticulate almost throughout, more densely so above, plane to erect; costa short and single or double or absent; cells linear-flexuose, smooth, thick-walled, the lumina scarcely wider than the walls, not or scarcely porose; alar cells subquadrate, extending up margins by ca. 5 cells and across the insertion by 6-8 cells. Secondary stem and branch leaves complanate, wide-spreading, oblong-ovate, ca. 2 mm long (to 4 mm long extralimitally), acute, sometimes abruptly so, undulate above, ± concave, subcordate at base, narrowly short-decurrent; margins strongly serrulate above, mostly plane, sometimes erect to narrowly recurved below; costa short and double with one fork sometimes to 1/3 the leaf length; cells ± linear-flexuose, ca. 10:1, 5-6 µm wide, smooth, firm-walled, subporose; alar cells subquadrate, ± confined to areas of decurrencies, often yellowed across the insertion. Asexual propagula none. Autoicous. Perichaetia conspicuous; leaves erect, convolute, broadly oblong-lanceolate, the innermost to 3 mm long (4 mm long extralimitally), gradually to ± abruptly acuminate, concave; margins subentire or bluntly notched at base of acumen, ± plane; costa absent or short and obscure; cells linear, smooth, thick-walled, porose. Setae very short, smooth, 0.14-0.18 mm extending from vaginula, ca. twice that length immersed in it, vaginular hairs longer than seta and reaching capsule base; capsules immersed, cylindric, erect and symmetric, ca. 1.5 mm long (to 2 mm extralimitally); exothecial cells short-rectangular, firm- to thick-walled, becoming oblate in 5-8 rows at the mouth; annulus not differentiated; operculum conic-rostrate, straight, ca. 0.85 mm long; exostome teeth pale, linear-triangular, ca. 0.6 mm long, inserted below the mouth, not bordered or shouldered, on the front surface cross-striolate below, lightly roughened to ± smooth above, not or scarcely trabeculate at back; endostome with a low, smooth to lightly roughened basal membrane, segments lightly roughened, keeled, narrowly perforate, ca. 2/3 the length of the teeth, cilia none. Spores spherical, densely papillose, 17-22(-28 extralimitally) µm diam. Calyptrae cucullate, naked, ± smooth.
1. Neckera scabridens Müll. Hal., Bot. Zeitung (Berlin) 5: 828. 1847. Plate 39, figures 1-7 Neckera lindigii Hampe, Linnaea 32: 149. 1863. Neckera bogotensis Mitt., J. Linn. Soc., Bot. 12: 454. 1869. Range. Costa Rica, Colombia and Venezuela south to northern Argentina and central Chile, southeastern Brazil; Hispaniola (Dominican Republic); growing epiphytically on twigs and small branches, in humid hardwood forests, at ca. 2000 m. This species, occurring at the northernmost extension of its range in the Dominican Republic, is known from only two collections (Bolay 61, Buck 14667, both NY) in the Sierra de Baoruco, Prov. Independencia. Discussion. Neckera scabridens is characterized by oblong-ovate leaves with acute apices and thick-walled laminal cells. The perichaetia are large and conspicuous and completely enclose the immersed capsules. The exostome teeth are cross-striolate below. In comparison to N. urnigera, N. scabridens is separated by immersed capsules. When plants are sterile (a rare condition), N. scabridens may be told by its leaves with a better developed alar region.