Forsstroemia producta (Hornsch.) Paris

Plants medium-sized, forming tufts or rarely scattered and gregarious, green to yellow-green; corticolous to saxicolous. Primary stems creeping; secondary stem erect, 15-40 mm long, branching ± regular in a single plane, pinnate; in section oval, central strand absent, inner cortical cells thin-walled, hyaline, in 4-6 rows, outer cortical cells thick-walled, yellow, in 2 or 3 rows; paraphyllia absent; pseudoparaphyllia narrowly foliose. Leaves crowded, widespreading wet, appressed dry; stem leaves ovate, 1.0-1.8 mm long; acute to acuminate; occasionally twisted at apex; rounded at base; margins plane, entire to weakly serrulate; branch leaves smaller but similar in other respects to stem leaves. Costa single, extending to midleaf or above, smooth; in section elliptical, consisting of three rows of undifferentiated cells. Upper laminal cells rhombic to quadrate, homogeneous, 11-20 µm long, 6-10 µm wide, walls thickened, smooth; basal cells not strongly differentiated, rectangular to fusiform, greenish, walls thickened, smooth; alar cells forming distinct groups, quadrate to transversely rectangular, green, walls thickened. Perigonia gemmate. Perichaetia strongly differentiated; leaves lanceolate-acuminate, 2-3 mm long, leaf cells linear and ± sigmoid. Seta 1-3 mm long, yellow, smooth. Capsule emergent to shortly exserted, ± erect, short-cylindrical, 1.0-1.5 mm long, smooth, yellow-brown; exothecial cells irregular-rectangular, walls thin, cells at mouth darker, quadrate to transversely rectangular; annulus absent; neck cells not differentiated; stomata absent. Peristome double, light yellow; exostome teeth fragile and irregular, linear, inflexed and closed wet, sigmoid and incurved dry; ± smooth cleft and perforated, with median zigzag line, 100-110 µm high; endostome segments rudimentary or sometimes absent with age. Operculum conic-rostrate, erect to curved. Calyptra cucullate, 3 mm long, weakly hairy. Spores rounded, 12-20 µm, granulate, brownish.