Terry J. O'Brien

Plants small to medium-sized, green or yellowish. Stems creeping, 1-pinnate or sometimes irregularly 2-pinnate; paraphyllia polymorphous, filiform or sometimes narrowly lanceolate, branched or sometimes unbranched, cells oblong, smooth or papillose over end walls, apical cell bluntly conic by wall thickened at tip; pseudoparaphyllia lanceolate or ovate-lanceolate, margins ciliate or serrate, proximal cells subquadrate, centrally papillose. Stem leaves spreading, broadly ovate or rarely elliptic; margins plane or recurved, spinose-serrate distally, entire or distantly serrulate in acumen; apex abruptly narrowed, acumen subulate; costa surface with coarse, spinose teeth over proximal 1/2; laminal cells with abaxial surface echinate, 1-papillose, papilla coarsely obliquely blunt-conic; medial cells subquadrate to short-rectangular; apical cell 20:1, smooth. Branch leaves differentiated from stem leaves, spreading or spreading-erect, slightly overlapping, ± catenulate when dry, broadly ovate, concave; apex abruptly acute; distal medial laminal cells irregular, rhombic, oblong, or subquadrate, walls incrassate; apical cell 7:1, with distal bluntly conic wall thickening. Sexual condition dioicous; perichaetial inner leaves with cilia present. Seta 2-2.8 cm. Capsule with stomata present in proximal 1/2. Spores 10-16 µm.

Species 1: nw North America, e Asia.

Lower Taxon

• Echinophyllum sachalinense (Lindberg) T. J. O'Brien