Forsstroemia trichomitria (Hedw.) Lindb.

Authority

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

Family

Leptodontaceae

Scientific Name

Forsstroemia trichomitria (Hedw.) Lindb.

Description

Species Description - Plants medium-sized, in green to golden, mostly thin but sometimes extensive, epiphytic colonies. Primary stems creeping, slender, inconspicuous, with reduced, scale-like leaves, turning ca. 90° and becoming the erect secondary stem, the creeping stem continuing by a bud from near the base of the secondary stem, secondary stems ± erect, subpinnately branched, to ca. 4 cm long, but often only 2 cm, not or scarcely complanate-foliate; in crosssection with 2-4 rows of small thick-walled cells surrounding larger thinner-walled cells, central strand none; paraphyllia none; pseudoparaphyllia filamentous to narrowly foliose; axillary hairs with a single short brown basal cell and 2-3 elongate hyaline distal cells. Secondary stem and branch leaves similar but branch leaves smaller, appressed when dry, rapidly erect-spreading when moist, ovate-lanceolate to oblong-ovate, (1.2-) 1.4-1.9(-3) mm long, gradually to ± abruptly short-acuminate, concave, not or somewhat plicate, shortly but broadly decurrent; margins subentire to serrulate above, entire below, plane above, recurved below; costa single, slender, ending to ca. 2/3 the leaf length, sometimes much shorter or short and double; cells rounded long-hexagonal, ca. 5-8:1, smooth, firm- to thick-walled, subporose, becoming shorter toward the margins and there ca. 1-2:1, becoming conspicuously porose toward the insertion; alar cells subquadrate to oblate, in extensive areas, not reaching the costa, extending up the margins to ca. 1/3 the leaf length and there scarcely different from marginal cells. Asexual propagula none. Autoicous. Perichaetial leaves erect, ± convolute, lanceolate to ovate, to ca. 4.5 mm long, slenderly acuminate; costa single or absent; cells long-hexagonal, smooth, firm- to thick-walled, sometimes porose. Setae short, smooth, reddish, 1-3.5 mm long, often twisted when dry, straight when moist, from a hairy vaginula; capsules typically short-exserted, sometimes immersed to emergent, erect and symmetric, cylindric. 1-2 mm long; exothecial cells short-rectangular, ca. 2:1, thin-walled; annulus not differentiated; operculum obliquely conic-rostrate, to 1 mm long, usually shorter; exostome teeth pale, linear-triangular, smooth to obscurely papillose, on the front surface with a ± straight median line, not trabeculate at back; endostome fragmentary but usually conspicuous and adhering to exostome. Spores spherical, finely papillose, 17-30(-40) µm diam. Calyptrae cucullate, hairy, the hairs usually biseriate at their bases, uniseriate above, smooth.

Discussion

1. Forsstroemia trichomitria (Hedw.) Lindb., Öfvers. Fõrh. Kongl. Svenska Vetensk.-Akad. 19: 605. 1863; Pterigynandrum trichomitrion Hedw., Sp. Muse. Frond. 82. 1801; Leptodon trichomitrion (Hedw.) D. Mohr, Observ. Bot. 27. 1803; Lcisia trichomitria (Hedw.) P. Beauv., Prodr. Aethéogam. 72. 1805; Pterogonium trichomitrion (Hedw.) Schwagr., Sp. Muse. Frond. Suppl. 1(1): 107. 1811; Neckera trichomitria (Hedw.) Müll. Hal., Syn. Muse. Frond. 2: 116. 1850; Dusenia trichomitria (Hedw.) Müll. Hal. ex M. Fleisch., Hedwigia 59: 213. 1917, nom. inval. Plate 63, figures 1-8 Discussion. Forsstroemia trichomitria is recognized by subpinnately branched secondary stems, narrowly oblong-ovate leaves, slender single costa, elongate laminal cells, extensive alar cells, emergent to shortly exserted capsules, and hairy calyptrae. It is unlikely to be seriously confused with any other moss in our flora. Superficially it may resemble Leucodon, but in that genus the costa is consistently short and double or absent. Any confusion with the Pterobryaceae can be resolved by the broader, less numerous pseudoparaphyllia.

Distribution

Range. Eastern North America, Mexico, southern South America, eastern Asia, eastern Australia [as subsp. australis (Müll. Hal.) L. Stark]; Hispaniola (Dominican Republic); growing on tree trunks (hardwoods) and rocks in shaded, humid areas, especially near streams, at 540-1400 m.

North America| Mexico North America| Chile South America| Argentina South America| Brazil South America| Bolivia South America| Peru South America| Paraguay South America| Uruguay South America| China Asia| Japan Asia| South Korea Asia| North Korea Asia| Taiwan Asia| Mongolia Asia| Australia Oceania|