Bryum ruderale Crundwell & Nyholm, Bot. Not. 116: 95. 1963

Plants small, green or yellow-green, often with reddish tinge. Stems 0.4-2(-3) cm; rhizoids red-violet to deep red. Leaves loosely set, ovate-lanceolate, weakly concave, 0.4-1(-1.5) mm; base not decurrent; margins plane to weakly revolute proximally, entire to serrulate distally, limbidium absent; apex acute; costa short-excurrent, awn stout; alar cells similar to adjacent juxtacostal cells; proximal laminal cells abruptly quadrate to short-rectangular, 2-4:1; medial and distal cells (30-)40-60 × 8-14 µm, 3-4:1. Specialized asexual reproduction by rhizoidal tubers, on long rhizoids in soil, purple-red or rarely orange, irregularly spheric, (120-)150-200 µm, cells 25-50 µm, smooth. Sexual condition dioicous. [Capsule inclined or nutant, 1-3 mm].

Damp disturbed soil, sand; low to moderate elevations (0-1200 m); Ont.; Ariz., Calif., La., Tex.; Eurasia; n, s Africa; Atlantic Islands (Macaronesia); Pacific Islands (New Zealand).

Gemmabryum ruderale is characterized by red-purple to violet rhizoids and relatively large, spheric, purple-red rhizoidal tubers. In the flora area, this species is probably introduced.