Brothera leana C. Müller 1900

This species often produces abundant clusters of brood bodies in axils of the upper leaves and appears to have grayish sheen, which is easily recognized in the fields.

Brothera leana is easily identified by clusters of brood leaves always present in the comal tufts. Campylopus fragilis has a similar appearance, but it has a different transverse section of the costa, with dorsal instead of median stereids. Furthermore, the ranges of the two species in North America do not overlap.

Plants small, 3–8 mm high, green or yellowish green with grayish sheen, in dense, compact tufts. Stems radiculose at the base, with many small, spindle-shaped brood bodies clustered in axils of the upper leaves. Leaves linear-lanceolate, 3.0–3.6 mm long, gradually narrowed from a short, tubulose base, subtubulose above; margins entire or slightly serrulate at the tips; costa broad, filling 1/3 – ½ or more of the leaf base width and nearly all of the subula; laminal cells thin-walled, rectangular above, marginal cells somewhat elongate, laxer at the base; alar cells not clearly differentiated. Setae ca. 8 mm long, reddish brown; capsules reddish brown, ca. 1.0 mm long, 0.5 mm in diameter, without stomata. Spores 10–15 µm in diameter, pale yellowish, mostly smooth.

Leaves 2-3 mm; margins entire; costa 155-180 µm wide; basal laminal cells 19-55 × 4-19 µm, narrower at margins; distal laminal cells 24-55 × 3-7 µm. Specialized asexual reproduction by clusters of spindle-shaped brood leaves in the comal tufts. Sporophytes not found in North America.

Distribution: China, India, Korea, Japan, Russia (Siberia), and North America.

Habitat: on tree bases or rotten wood, and rarely on rocks.

Leucophanes leanum Sullivant, Musc. Allegh., 41. 1846; Campylopus leanus (Sullivant) Sullivant & Lesquereux; Leucobryum leanum (Sullivant) Kindberg; Syrrhopodon leanus (Sullivant) Lesquereux & James