Plants 4--50 cm, coarse, prostrate or dendroid, forming yellow-green to blackish sods or mats. Stems 4--15(20) cm, dark reddish-brown to black, densely matted with dark reddish-brown rhizoids at base, often defoliate proximally; branching subpinnate distal to a more or less naked stem; branches 1--8(--13) cm, occasionally producing flagelliform branches; pseudoparaphyllia foliose; paraphyllia lacking. Stem leaves smooth, spreading, ovate-oblong or ovate-lanceolate, acuminate or cuspidate, keeled, somewhat contorted when dry, 1.5--3.5 mm, proximal leaves scale-like and erose, elongate-triangular to deltoid, plicate, tapering to an often subulate, flexuose tip; margins plane, 1-stratose, 1--2 cells wide, serrulate to serrate, occasionally entire, sometimes forming basal auricles 2--10 cells wide, with conspicuous, usually submarginal limbidia of (2--)4 layers of incrassate cells, usually disappearing near acumen, sometimes with spurs extending into the lamina, and often absent in the most proximal leaves; costa single, strong, percurrent to shortly excurrent; distal laminal cells subquadrate to rhomboidal, 3--36  3--18 µm, 1-stratose, smooth; basal cells mostly oblong, walls at insertion incrassate, sparingly pitted, often yellow, 7--77  3--18 µm. Branch leaves similar to stem leaves, but with limbidia strong, disappearing very near acumen, or confluent with costa, to 3.5 mm. Sexual condition dioicous. Perichaetial leaves erect, lanceolate, long-acuminate, squarrose, serrulate distally or entire, costate but lacking limbidia, 1--2.5  0.8--1 mm. Seta single, reddish-brown, straight or flexuose, often tortuose in aquatic plants, 1.5--3.5 cm, smooth. Capsule horizontal to cernuous, oblong-cylindric, asymmetrical, sometimes arcuate, reddish-brown, 1.5--3 mm, usually shrunken under the mouth when dry; exothecial cells quadrate to rounded-rectangular; stomata superficial; annulus of 2--3 rows of cells, deciduous; operculum conic-apiculate to rostrate; peristome hypnoid, exostome teeth 16, yellowish-brown, lanceolate, sometimes cribrose at base, cross-striolate below, papillose above, trabeculate at back; endostome hyaline or pale yellow, with high basal membrane, cilia appendiculate. Calyptra cucullate, naked, cylindric, early-deciduous. Spores 14--18 µm, minutely papillose, green.

Species 2 (1 in the flora): Oregon, Hawaii.

Species of Limbella previously have been included in Sciaromium (Mitten) Mitten, a synonym of Echinodium Juratzka (S. P. Churchill 1986).

SELECTED REFERENCES

Christy, J. A. 1987. Limbella fryei (Williams) Ochyra distinct from L. tricostata (Sull.) C.M. (Musci: Amblystegiaceae). J. Hattori Bot. Lab. 63: 395--410. Ochyra, R. 1987. On the taxonomy and family placement of the moss genus Limbella (C. Muell.) Broth. J. Bryol. 14: 465--485.

OTHER REFERENCES

Christy, J.A. 1980. Rediscovery of Sciaromium tricostatum (Sull.) Mitt. (= Limbella tricostata (Sull.) Bartr.) in North America. Bryologist 83: 521--523.
Churchill, S. P. 1986. A revision of Echinodium Jur. (Echinodiaceae: Hypnobryales). J. Bryol. 14: 117--133.
Lawton, E. 1971. Moss Flora of the Pacific Northwest. Hattori Botanical Laboratory, Nichnan, Japan.

Lower Taxon

• Limbella fryei (R. S. Williams) Ochyra

Related Synonym(s):

• Sciaromium fryei R. S. Williams = Limbella fryei (R. S. Williams) Ochyra