Bryum coronatum Schwagrichen, Sp. Musc. Frond. Suppl. 1(2): 103, plate 71 [top]. 1816

Plants green or yellow-green. Stems 0.5-1(-2) cm, gemmiform to evenly foliate. Leaves ovate-lanceolate to triangular, weakly concave, 0.5-1.5(-2) mm; margins revolute to mid leaf or beyond; apex acute to acuminate; costa short-excurrent; proximal laminal cells abruptly quadrate to short-rectangular, 1-2:1; medial and distal cells 8-12(-16) µm wide, 3-4:1. Specialized asexual reproduction by leaf axil bulbils, bulbils 1 (or 2) per axil, elongate-ovate, 250-750µm, primordia present, broadly triangular, acute, arising from just below mid bulbil or near base. Capsule nutant, purple-red at maturity, 1-3(-4) mm; hypophysis strongly thickened, inflated, strongly rugose; peristome well developed; endostome not adherent to exostome, basal membrane high, segments well developed, perforations ovate, cilia long, appendiculate.

Capsules mature Apr-Jul (spring-summer). Moist soil, soil over rock; low to moderate elevations (0-500 m); Ala., Fla., Ga., La., Miss., S.C., Tex.; Mexico; West Indies; Central America; South America; se Asia (including Indonesia); Africa; Pacific Islands; Australia.

Gemmabryum coronatum is similar to G. dichotomum but tropical-subtropical to warm-temperate in distribution, with strongly revolute leaf margins and often triangular leaves. Another feature is the strongly thickened hypophysis, almost as though inflated and distinctly rugose, which in G. dichotomum is less thickened and more or less smooth.