Porotrichum madagassum Kiaer ex Besch.

Plants medium-sized to large, in loose colonies, green to yellow-green; saxicolous or sometimes corticolous. Primary stems long-creeping; secondary stems erect, 60-100 mm long, branching irregular above stipe, ± dendroid; in section round to oval, central strand small, inner cortical cells thin-walled, in 12-14 rows, outer cortical cells thick-walled, red-brown, in 8-10 rows. Leaves somewhat crowded, flattened, erect-appressed; stem leaves broadly ovate to elliptical, 1.5-2.5 mm long; acute to short-acuminate; narrowed to insertion; margins plane, serrate above, entire below; branch leaves ovate to elliptical, somewhat smaller. Costa single, extending to midleaf or above, smooth, not ending in spine; in section elliptical, of 2 or 3 rows of undifferentiated cells. Upper laminal cells rhomboidal to somewhat fusiform, homogeneous, 20-40 µm long, 5-6 µm wide, walls weakly thickened, smooth; basal cells ± oblong, not strongly differentiated, 35-65 µm long, 6-8 µm wide, greenish, walls thickened and pitted, smooth; alar cells not differentiated. Perigonia gemmate. Perichaetial leaves oblong-acuminate, to 3 mm long, leaf cells oblong, thickened and pitted. Seta 10-15 mm long, red-brown, smooth. Capsule exserted, erect, ovoid, 1.5-2.0 mm long, smooth, red-brown; exothecial cells ± hexagonal, walls thin; cells at mouth rounded; annulus present, differentiated; stomata phaneropore on neck. Peristome double, yellow; exostome teeth linear, recurved dry, inflexed wet, papillose-striate, with median zigzag line or perforated along midline, 700-800 µm high; endostome segments linear and perforated above low basal membrane, as long as teeth, papillose; cilia absent. Operculum obliquely rostrate, 1 mm long. Calyptra cucullate, ± smooth. Spores rounded, 18-20 µm, papillose, brownish.