5. Trichodon Schimper, Coroll. Bryol. Eur. 36. 1856.
[Greek trichos, hair, and odon, tooth, alluding to slender divisions of peristome]
Robert R. Ireland Jr.
Plants scattered or in loose tufts, light- to yellowish green. Stems 0.2-0.4 cm, simple; rhizoids at base, papillose. Leaves slightly contorted when dry, subulate, tubulose, base broad and sheathing; margins plane or incurved, serrate to enlarged portion of leaf base; costa percurrent to excurrent, filling distal part of subula, strongly prorulose on abaxial surface; medial laminal cells rectangular, sometimes quadrate and irregularly angled on margins, smooth or prorulose. Specialized asexual reproduction sometimes present, as smooth, round or irregularly shaped tubers on rhizoids. Sexual condition dioicous; male and female plants about the same size; perichaetial leaves not differentiated. Seta yellow to red, elongate, erect. Capsule erect to inclined, exserted, yellowish to reddish brown, cylindric, slightly curved or sometimes straight, smooth; annulus of 1-3 rows of large cells, deciduous; operculum conic to short-rostrate; peristome single, teeth 16, divided nearly to base to form two filiform segments, papillose. Calyptra cucullate. Spores globose, minutely papillose.
Species 2 (1 in the flora): North America, Europe, Asia in boreal and arctic areas.
Ireland, R. R. 1978. Trichodon in North America. Bryologist 81: 150-154.