Bryum dichotomum Hedw.

Plants small, loosely caespitose to caespitose, yellowish green to green above, brownish below; terricolous. Stems 3-15 mm tall, simple or branching by subperichaetial innovations, occasionally tomentose below; rhizoids reddish to reddish brown, papillose, tubers 100-360 µm, brown. Leaves comose, erect to erect-spreading when dry, erect-spreading when wet, slightly concave; ovate to ovate-lanceolate or lanceolate, (0.3-)0.5-1.0(-1.2) mm long; apex acuminate; margins plane to recurved below, entire to denticulate above; border absent. Costa strongly aristate, awn 80-340(-480) µm long, smooth to denticulate above, yellowish green or reddish; in section round, laminal insertion ventral, ventral surface cells present, dorsal stereid band strong, dorsal surface cells incrassate, hydroids present between guide cells and stereid band. Upper laminal cells rhomboidal, thin-walled to incrassate, 22-68 µm long, 7-15 µm wide; basal cells rectangular to quadrate, occasionally reddish below. Propagulae bud-like, axillary, 180-600 µm long. Dioicous. Perichaetia terminal, leaves lanceolate to triangular. Seta 6-15(-22) mm long, yellowish or red to reddish brown; capsule horizontal to pendulous, ovoid or shortly oblong-cylindrical, 0.8-1.8 mm long, dark red or reddish brown when mature, slightly contracted below mouth when dry, neck short, frequently broadly rounded to seta, wrinkled when dry; exothecial cells irregular in shape, incrassate, smaller towards mouth; peristome double, exostome teeth yellow to orange, endostome segments tapering above, widely perforated, cilia 2-3, appendiculate, basal membrane high, finely papillose, yellowish; operculum mammillate; spores 8-10 µm, minutely papillose.