22. Wijkia (Mitt.) Crum 刺枝藓属 ci zhi xian shu
Bryologist 74: 170. 1971. Acanthocladium Mitt., Proc. Linn. Soc. New South Wales 7: 102. 1883, hom. illeg.
Plants slender or robust, more or less stiff, usually forming weft, light green or yellowish green, sometimes brownish yellow, glossy. Stems creeping, with loose rhizoids, irregularly 1–2-pinnately branched; branches patent-spreading or complanate, sometimes slightly curved; apices of stems and branches straight; paraphyllia few. Leaves appressed when dry, erect, patent-spreading when moist; stem and branch leaves differentiated; stem leaves ovate, concave, acuminate or abruptly forming a long filiform acumen; margins entire or serrulate above; costae double, very short or none; leaf cells narrowly rhomboidal, thin-walled, usually smooth, rarely unipapillose, or prorate; basal cells often golden yellow, thick-walled, pitted; alar region consisting of one row of evidently differentiated cells, large, elongated-oblong, golden yellow or brownish yellow, sometimes hyaline, the other alar cells small, thin-walled, hyaline short; branch leaves smaller, acuminate, margins serrate. Dioicous. Inner perichaetial leaves erect, not plicate, sheathing at base, slender and long acuminate toward apex, margins serrate above. Setae slender and elongate, purple, smooth; capsules horizontal, cylindrical, slightly arcuate, constricted when dry or mature; opercula conic, short or long rostrate above, rarely rounded obtuse with a short tip; annuli differentiated; peristome double; outer surface of exostome teeth cross-striate below, papillose above, inner surface highly trabeculate; endostome segments as long as the teeth; basal membrane keeled; cilia 1–2. Calyptrae not seen. Spores variable in size, irregularly rounded, yellowish green, smooth.