Pyrrhobryum

Stems with exterior cells in 2 or 3 rows, small, walls thick, interior cells larger, walls moderately thick. Leaves with base undifferentiated or occasionally indistinctly decurrent; margins double-serrate from near base; costa stereid cells well developed on both sides of guide cells; juxtacostal basal cells often weakly differentiated, short- to long-rectangular, enlarged, lax or not; medial and distal laminal cells uniform, isodiametric, rounded to 4–6-sided, smooth, walls thick; marginal cells 2-stratose. Seta wiry. Capsule striate and flared at mouth when deoperculate; exothecial cells hexagonal [quadrate- to rectangular-rounded], walls moderately thick, somewhat weakly collenchymatous at base; stomata few at base and in neck, superficial.

Distribution

se United States, Mexico, West Indies, Central America, South America, Asia, Africa, Pacific Islands, Australia, pantropical and southern temperate regions.

Discussion

Species 10 (1 in the flora).

Pyrrhobryum is characterized by elongate stems, distal and spirally arranged, broadly to narrowly lanceolate or linear-lanceolate leaves with double-toothed, 2-stratose margins, costae distally toothed abaxially, laminal cells mostly isodiametric and similar to near bases, and sporophytes positioned somewhat midway on stems or at bases.

Selected References

Frahm, J.-P. et al. 2003. Synopsis der Gattung Pyrrhobryum (Musci, Rhizogoniaceae). Trop. Bryol. 24: 115–127.

Lower Taxa

Pyrrhobryum spiniforme