Taxon	Illustrator ⠉
	Conostomum tetragonum	Patricia M. Eckel

Plants in dense tufts, glaucous or yellow-green. Stems 0.5–3 cm, erect, simple or 2-fid; pentagonal in cross-section, hyalodermis present, epidermis not prorulose; radiculose proximally, rhizoids smooth. Leaves in 5 distinct rows, imbricate, appressed when dry or moist, narrowly lanceolate, 1-stratose; base not sheathing; margins slightly revolute in distal 1/2, serrulate near apex, teeth single; apex acuminate or rarely blunt; costa percurrent to excurrent, sometimes subpercurrent in proximal leaves, abaxial surface mammillose-toothed; basal laminal cells more lax than distal cells; distal cells rectangular to short-rhomboidal, smooth or mammillose at distal ends on both surfaces, walls thick. Specialized asexual reproduction unknown. Sexual condition dioicous [or autoicous]; perigonia cupulate or gemmiform; perichaetial leaves larger than stem-leaves. Seta single, elongate, flexuose. Capsule erect to inclined, ovoid, wrinkled and furrowed when dry, mouth not small, not oblique; annulus absent; operculum conic, rostrate; peristome single or rarely absent; exostome teeth reddish orange to dark-brown, linear-lanceolate, smooth throughout or finely papillose basally, apically connate. Spores spheric to reniform, coarsely papillose [to smooth].

Distribution

North America, Mexico, West Indies, South America, Europe, Asia, Africa, Pacific Islands

Discussion

Species 7–15 (1 in the flora).

Selected References

None.

Lower Taxa

Conostomum tetragonum