Rhizomnium striatulum

Description

Plants 1-8(-12) cm, in tufts or mats. Stems red or reddish brown, becoming darker, sometimes black when old, usually erect, rarely sinuate at maturity or sterile stems sometimes arching, usually simple, not dendroid; rhizoids brown, macronemata often matted proximally, mainly restricted to stem bases distally, not in longitudinal rows, micronemata present or absent. Leaves green, dark green, or occasionally reddish, reddish brown, or yellow-green, somewhat contorted when dry, erect-spreading and flat, sometimes undulate when moist, obovate, elliptic, or rarely - orbicular, 1-7(-13) mm; base narrowly short- to long-decurrent; margins plane, green, reddish, or brown, rarely blackish with age, 1-4-stratose, entire; apex usually rounded, occasionally retuse or emarginate, sometimes apiculate; costa ending well below apex (to about 7/8 leaf length and often 2-fid distally), subpercurrent, or percurrent, distal abaxial surface smooth; medial laminal cells elongate, sometimes short-elongate or - isodiametric, 35-180 -m, sometimes in weakly developed diagonal rows, usually collenchymatous, walls pitted or not; marginal cells differentiated, linear, rhomboidal, or rectangular, in (1-)2-3(-6) rows. Specialized asexual reproduction absent (sometimes by green protonematous rhizoids in R. punctatum). Sexual condition dioicous or synoicous. Seta single, reddish brown, occasionally orange, often pale, 1-5 cm, straight to somewhat flexuose. Capsule horizontal to pendent, yellow or yellowish brown, elliptic, ovate, subglobose, oblong, or cylindric, 1-4.5 mm; operculum conic, conic-apiculate, or conic-rostrate; exostome yellow or brown when mature; endostome yellow or yellowish brown, . Spores 25-50 -m.