Pilotrichum bipinnatum (Schwägr.) Brid.

Authority

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

Family

Pilotrichaceae

Scientific Name

Pilotrichum bipinnatum (Schwägr.) Brid.

Description

Species Description - Plants medium-sized, in ± lustrous, yellow-green to golden-brown, often small patches. Stems creeping, with small, broadly triangular, broadly inserted leaves, the primary branches erect, 3.512 cm long, usually 5-8 cm long, irregularly bipinnate from regularly pinnate branches; in cross-section with 5-8 rows of small thick-walled colored cells surrounding larger ± thin-walled cells, central strand none; pseudoparaphyllia filamentous; axillary hairs 2-celled, with a short brown basal cell and an elongate hyaline distal cell. Secondary branch leaves fairly crowded, erect to erect-spreading when dry, erect-spreading when moist, scarcely altered, ovate to obovate, 0.6-1 mm long, gradually to abruptly acute to short-acuminate, concave, slenderly short-decurrent; margins serrulate above, subentire below, plane throughout or irregularly narrowly recurved; costa double, mostly unequal, ± parallel in upper 1/2, usually ending ca. the leaf length, sometimes longer, not crested or with a low crest 1 cell high; cells long-oblong, smooth to prorulose, thick-walled with the cell walls often wider than the lumina, scarcely porose, apical cells often longer, becoming rectangular, porose, and colored toward the insertion and decurrencies; alar cells not differentiated. Asexual propagula not produced. Synoicous. Perichaetia ± conspicuous, on primary branches or bases of secondary ones; leaves erect, oblong, 0.6-1.1 mm long, ± abruptly acute to short-acuminate; margins subentire throughout or serrulate at extreme apex, plane or sometimes erect; costa double, faint, ± divergent, ending near midleaf, sometimes absent, not crested; cells rounded-oblong to linear, smooth to low-prorulose, thick-walled, ± porose, becoming broader and colored toward the insertion. Setae short, stout, smooth, reddish, 1-1.3 mm long, usually curved; capsules exserted, erect, cylindric, symmetric, ca. 1-2 mm long; exothecial cells short-rectangular, thin- to firm-walled, not collenchymatous; annulus of a single row of subquadrate, thick-walled cells; operculum short-rostrate from a high-conic base; exostome teeth pale, narrowly triangular, narrowly bordered, not shouldered, on the front surface with a straight or obscurely zig-zag median line, papillose-spiculose throughout, slightly trabeculate at back; endostome pale, papillose-spiculose, with a low basal membrane, segments slender, keeled, not perforate, as long as or longer than the teeth, cilia none. Spores spherical, occasionally oval, almost smooth, 14-18 µm diam. Calyptrae mitrate, lobed at base, naked (except for a few archegonia) or sometimes sparsely hairy, the hairs ± straight, uniseriate, smooth.

Discussion

13. Pilotrichum bipinnatum (Schwágr.) Brid., Muscol. Recent. Suppl. 4: 140. 1819; Neckera bipinnata Schwägr., Sp. Musc. Frond. Suppl. 1(2): 156. 1816; Daltonia bipinnata (Schwágr.) Arn., Mém. Soc. Hist. Nat. Paris 2: 303. 1826; Hookeria bipinnata (Schwágr.) Spreng., Syst. Veg. 4: 197. 1827; Callicosta bipinnata (Schwägr.) Müll. Hal., Linnaea 21: 188. 1848. Plate 29, figure 13; plate 35, figures 6-11 Discussion. Pilotrichum bipinnatum is distinctive in its synoicous inflorescences and lack of propagula. The plants are regularly branched with ovate leaves with apical cells conspicuously longer than subapical ones. Also, unlike most of the other Pilotrichum species, P bipinnatum is scarcely altered when moist. Distinctions from the closely related P. fenclleri are discussed under that species.

Distribution

Range. Guatemala to Panama, Venezuela and Colombia to Peru, the Guianas, Brazil, Trinidad and Tobago; Jamaica, Guadeloupe, Dominica, St. Vincent, Grenada; growing on tree trunks and branches, often slender twigs, in humid forests, often near streams, below 500 m, occasionally to 1400 m.

Central America| Venezuela South America| Colombia South America| Peru South America| Guyana South America| Suriname South America| French Guiana South America| Brazil South America| Trinidad and Tobago South America| Jamaica South America| Guadeloupe South America| Dominica South America| Saint Vincent and the Grenadines South America| Grenada South America|