Brymela

• Authority

  Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.

• Family

  Pilotrichaceae

• Scientific Name

  Brymela

• Description

  Genus Description - Plants medium-sized or often robust, in lustrous, yellow-green to golden or brownish, usually fairly limited mats. Stems creeping, sometimes ± pendent, red, ± regularly pinnate to scarcely branched, the branches not differentiated, evenly foliate but sometimes complanate; in cross-section without a hyalodermis, with several rows of small thick-walled cells surrounding numerous larger thinner-walled cells, central strand none; rhizoids laxly tufted on lower surfaces of bases of stems, smooth or slightly roughened; pseudoparaphyllia none or ± foliose but branches mostly arising in leaf axils; axillary hairs typically 2-celled, with a short brown basal cell and an elongate hyaline distal cell. Leaves crowded, scarcely altered when dry, the lateral and dorsal/ventral leaves not differentiated except in orientation, rarely complanate, oblong to ovate, mostly acute, sometimes obtuse or acuminate, often undulate, slightly concave, rounded at the insertion, sometimes subauriculate; margins not bordered, serrulate throughout, more densely and sharply so above, sometimes entire below, mostly plane; costa double, ending above midleaf, ± diverging throughout or ± parallel above, not or only sli htl projecting above; cells long-rectangular to linear, smooth or prorulose, thick-walled, the walls often as wide as the lumina ® ecially in larger species), porose, homogeneous throughout leaf, not becoming larger toward insertion except in a few rows at extreme base, there broader, shorter, and mostly colored; alar cells not differentiated. Asexual propagula not seen. Dioicous. Perichaetia fairly conspicuous or not; leaves similar to vegetative leaves but usually with a longer apex and longer cells, sometimes cells toward insertion larger. Setae elongate, roughened above, rarely smooth or roughened throughout, reddish; capsules suberect to horizontal, cylindric, fairly large; exothecial cells rectangular, irregularly thickened, obscurely collenchymatous; annulus usually present, falling with the operculum; operculum rostrate from a conic base; columella broadly cylindric, 1/2 as long as the urn or shorter, sometimes the apex broader than the base; peristome double, attached at the mouth, exostome teeth narrowly triangular, bordered, not shouldered, on the front surface with a median furrow, the plates cross-striolate below, coarsely papillose above, slightly trabeculate at back; endostome with a fairly high basal membrane, segments keeled, not perforate, with baffle-like crosswalls, almost as long as the teeth, cilia none. Spores spherical, finely papillose, often large. Calyptrae mitrate, lobed at base, naked or with a few hairs, smooth.

• Discussion

  Brymela Crosby & B. H. Allen, Monogr. Syst. Bot. Missouri Bot. Gard. 11(Contr. Syst. Bot. ded. L. E. Anderson): 211. 1985. Discussion. Brymela was described for a single, distinctive Panamanian species, B. tutezona Crosby & B. H. Allen. Although Crosby and Allen (1985) thought their plant generically distinct from B. parkeriana, with which they compared it, I disagree (Buck, 1987a). The leaves with only serrulate margins, thick-walled and porose cells homogeneous throughout, and subauriculate insertions, as well as the often roughened seta apices, though, do seem to circumscribe a natural group of species previously placed in Hookeriopsis and occurring in the West Indies, southern Central America, and northern South America. Hookeriopsis, here defined in a strict sense, has only two species and is characterized by a short, double costa and concave leaves. Brymela is most easily confused, superficially, with species of Thamniopsis because many of those species also have undulate leaves. However, in that genus the stem has a hyalodermis, the leaves are often sharply serrate rather than serrulate, and the basal laminal cells are considerably larger than the apical ones, both of them thin-walled and not porose.