Thamniopsis cruegeriana (Müll.Hal.) W.R.Buck

Authority

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

Family

Pilotrichaceae

Scientific Name

Thamniopsis cruegeriana (Müll.Hal.) W.R.Buck

Description

Species Description - Plants relatively robust, in ± lustrous, green or golden, ± lax, extensive mats. Stems creeping, to ca. 12 cm long, subpinnately branched, the branches differentiated, densely foliate, obscurely complanate-foliate; in cross-section with a single row of large thin-walled cells over (1-)2-3 rows of small thick-walled cells surrounding numerous large thin-walled cells, central strand none; pseudoparaphyllia small, foliose; axillary hairs 2-celled, with a short brown basal cell and an elongate hyaline distal cell. Branch and stem leaves differentiated in orientation, shape, and margins, stem leaves ± spreading, little altered when dry, ovate to oblong-ovate, 1.4-1.7(-2.2) mm long, broadly rounded to stoutly and bluntly mucronate, less often ± abruptly acuminate, not undulate, margins obscurely bordered by 4-7 rows of elongate cells, especially conspicuous at midleaf, subentire to serrulate, in acuminate leaves the margins ± serrate with short, bifid teeth, plane; branch leaves erect to erect-spreading, oblong to oblong-lanceolate, 1.4-2.1 mm long, gradually or ± abruptly acuminate, undulate, especially above, more strongly so when dry, margins obscurely bordered by 3-6 rows of elongate cells, especially conspicuous at midleaf, sharply serrate above from short, swollen, mostly bifid cells, subentire below, plane; costa double, ± parallel, ending 3/4-4/5 the leaf length, somewhat unequal, conspicuously toothed in upper 1/2; cells long-hexagonal to long-rhomboidal, 6-8 µm wide, smooth or occasionally prorulose from upper cell ends, firm-walled, porose, becoming long-rectangular in basal ca. 1/5 of leaf, 12-15 µm wide, with 1(-2) rows of oval cells across the insertion, sometimes colored; alar cells not differentiated. Asexual propagula none. Dioicous. Perichaetia inconspicuous; leaves erect with spreading to recurved apices, abruptly long-acuminate from a broadly oblong base, 2-2.7 mm long; margins sharply serrate in acumen from short-celled, swollen, often bifid teeth, plane; costa double, ending ca. 1/3 the leaf length, below the base of the acumen; cells linear, firm-walled and porose in the acumen, long-hexagonal below. Setae elongate, smooth, reddish, 2.5-3 cm long, flexuose, curved at extreme apex; capsules horizontal to pendent, cylindric, ca. 2 mm long; exothecial cells rectangular, thin-walled throughout or with the vertical walls thicker; annulus of ca. 8-10 rows of thin-walled, subquadrate cells, sometimes falling with the operculum; operculum broadly rostrate from a conic base; exostome teeth reddish brown, bordered, on the front surface with a median furrow with a zig-zag line down it, the plates cross-striolate with overlying papillae below, coarsely papillose above the shoulder, slightly trabeculate at back, papillose; endostome with a high, smooth basal membrane, segments papillose-spiculose, keeled, not or narrowly perforate, with baffle-like crosswalls, ca. as long as the teeth, cilia none. Spores spherical, finely roughened, 9-14 µm diam. Calyptrae mitrate, lobed at base, naked or with a few hyaline uniseriate hairs, ca. 8 cells long, slightly roughened.

Discussion

2. Thamniopsis cruegeriana (Müll. Hal.) W. R. Buck, Brittonia 39: 218. 1987; Hookeria cruegeriana Müll. Hal., Syn. Musc. Frond. 2: 208. 1851; Hookeriopsis cruegeriana (Müll. Hal.) A. Jaeger, Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1875-76: 359. 1877. Plate 8, figures 1-13 Discussion. Thanmiopsis cruegeriana is characterized by differentiated branch and stem leaves, with the stem leaves typically with a broadly rounded subentire apex. The branch leaf apices are acute or acuminate and in the upper part of the leaf all the marginal cells form swollen, bifid teeth. In aspect it may be contused with T undata but the above technical features readily separate it. The most closely related species to T. cruegeriana is T. killipii (R. S. Williams) E. B. Bartram (= Hookeriopsis maguirei E. B. Bartram). In this northern South American species of higher elevations, the branch and stem leaves, like just the stem leaves in T cruegeriana, are entire. Although T. cruegeriana has been reported with a much wider range, I have only cited localities from which I have verified material because the species has been so widely misunderstood.

Distribution

Range. Venezuela, Trinidad; Barbados; growing on rocks or rotten logs, in humid forests, usually below 500 m.

Venezuela South America| Trinidad and Tobago South America| Barbados South America|