16. Hymenostylium Brid.   立膜藓属  li-mo xian shu

Bryol. Univ. 2: 181. 1827.

 

Plants medium-sized to rather large, to 30(–80) mm high, green to light brown, in dense tufts or cushions. Stems erect, often branched, radiculose at the base; central strand usually absent. Leaves appressed-contorted when dry, spreading to sometimes squarrose when moist, ligulate to lanceolate or linear-lanceolate, upper lamina often keeled, apex acute or occasionally rounded-obtuse or blunt; margins entire, plane or recurved; costa stout, percurrent to shortly excurrent, sometimes ending just below the apex, in cross section with two stereid bands; upper leaf cells quadrate to shortly rectangular or rhomboidal, with papillae low, simple or granular, lumens not obscured; basal cells different, rectangular, usually thin-walled, sometimes porose. Dioicous. Perichaetial leaves weakly differentiated, somewhat sheathing at the base. Setae elongate, yellowish brown to reddish; capsules ovoid to shortly cylindrical; annuli weakly differentiated; peristome absent; opercula conic-rostrate, with a long oblique beak. Calyptrae cucullate, smooth. Spores spherical, brownish, finely papillose.

 

One species and two varieties are known from China.

 

1. Leaf cells strongly trigonous, each cell usually with a large papilla, rarely with 2 papillae...............................

1. Leaf cells not trigonous, each cell usually with several small papillae.............................................................. 2

2. Leaves not sheathing at the bases; upper leaf cells rounded-hexagonal to rounded rectangular, rather thick-walled, irregularly arranged.............................................. 1a. H. recurvirostrum var. recurvirostrum

2. Leaves usually sheathing at the bases; upper leaf cells pentagonal to hexagonal, rather thin-walled, regularly arranged..................................................................................... 1c. H. recurvirostrum var. insigne