18. Scorpidium (Schimp.) Limpr. 蝎尾藓属 xie wei xian shu
Laubm. Deutschl. 3: 570. 1899. Hypnum subgen. Scorpidium Schimp., Syn. Musc. Eur. 650. 1860.
Plants medium-sized or rather large, yellowish green, reddish brown, or reddish black, in loosely caespitose mats. Stems prostrate or ascending, irregularly or subpinnately branched; in cross section cortical cells thick-walled, sometimes hyaline, enlarged; central strand weakly differentiated; rhizoids few, reddish brown, often present at base of costa; pseudoparaphyllia few, broad, foliose. Stem and branch leaves similar, erect or strongly secund toward one side, often abruptly curved above, broadly ovate, usually concave, obtuse or shortly acute, often cucullate at apex; margins nearly entire, only serrulate at apex; costae double, short or relatively strong; median leaf cells linear, smooth; basal cells shorter, broader, thick-walled, porose; alar cells somewhat differentiated, hyaline, rarely decurrent. Sporophytes not seen.