2. Trachyxiphium W. R. Buck, Brittonia. 39: 219. 1987. • [Greek trachys, rough, and xiphion, little sword, alluding to leaves marginally roughened by serrations].
Plants small [to large], soft, in dense mats, yellowish to brownish or golden green to nearly hyaline, glossy. Stems irregularly branched; hyalodermis absent. Leaves somewhat to occasionally clearly complanate, flaccid, somewhat flexuose, not crisped when dry, narrowly lanceolate to ovate-lanceolate, infrequently asymmetric; margins plane or broadly or narrowly recurved on one side, entire proximally, serrulate in distal 1/3; apex slenderly long-acuminate; costa 1/2-2/3 leaf length, ending in base of acumen, parallel to slightly divergent, distal abaxial surface strongly serrulate; laminal cells long-rhomboidal to linear, narrow, elongate, smooth or sometimes prorulose by projecting distal cell ends; marginal cells not forming border. Specialized asexual reproduction absent. Sexual condition synoicous (sometimes also with male and female gametoecia); perichaetial leaf apex subulate. Seta orange-brown, smooth. Capsule erect, inclined, or pendulous, ovoid; annulus absent; operculum obliquely and narrowly long-rostrate. Calyptra conic-mitrate, base fringed, often split on one side, smooth or distally slightly scabrous.
Species 15 (1 in the flora): se United States, Mexico, Central America, South America, Pacific Islands (Cocos Island).
Species of Trachyxiphium occur in the Neotropics on wet soil, rock, and logs, in humid lowlands to mid elevations, occasionally upper montane forests, from near sea level to 3400 m (S. R. Gradstein et al. 2001).
