Stereophyllum

• Authority

  Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.

• Family

  Stereophyllaceae

• Scientific Name

  Stereophyllum

• Description

  Genus Description - Plants medium-sized, in dull, pale- to yellow-green, sometimes brown-tinged, thin to dense, flat mats. Stems creeping, simple or sparingly and irregularly branched, subterete- or complanate-foliate; in cross-section without a hyalodermis, with small firm-walled cells surrounding large thin-walled cells, central strand absent; rhizoids smooth; pseudoparaphyllia filamentous; axillary hairs with a single short brown basal cell and 3-4 hyaline distal cells. Stem and branch leaves similar, crowded, ± stiff, usually imbricate and somewhat contorted when dry, erect-spreading when moist, complanate, oblong-ovate to nearly lingulate, abruptly acute to obtuse, sometimes apiculate, symmetric, flat or concave; margins entire or serrulate above, ± entire below, plane; costa single, stout, bulging on dorsal leaf surface; cells rhomboidal, typically unipapillose on both surfaces, sometimes smooth, ± firm-walled, not porose; alar cells distinctly differentiated, quadrate, rectangular or oblate, extending across adaxial surface of the costa, collenchymatous. Asexual propagula none. Autoicous, often fertile; perigonia scattered along stems, bracts ovate, acute, costate, cells rhomboidal throughout, smooth, firm-walled. Perichaetia at bases of stems; leaves oblong-ovate; margins serrulate, especially above; costa single; cells longer than in vegetative leaves, smooth, ± thick-walled. Setae elongate, smooth, straight or flexuose; capsules cemuous or rarely erect, straight to arcuate, ovoid to ellipsoid, not plicate, contracted below the mouth when dry; exothecial cells quadrate to short-rectangular, thin-walled, not collenchymatous; annulus differentiated; operculum short-rostrate, sometimes oblique; exostome teeth narrowly triangular, shouldered, bordered, on the front surface with a zig-zag median line, cross-striolate below, papillose above, trabeculate at back; endostome with a high basal membrane, segments keeled, perforate, almost as long as the teeth, cilia in groups of 1-3, shorter than the segments. Spores spherical to ovoid, papillose. Calyptrae cucullate, naked, smooth.

• Discussion

  Stereophyllum Mitt., J. Proc. Linn. Soc., Bot. Suppl. 1: 117. 1859. Hypnum sect. Glossophyllum Müll. Hal., Syn. Musc. Frond. 2: 229. 1851; Glossophyllum (Müll. Hal.) Hampe, Vi-densk. Meddel. Dansk Naturhist. Foren. Kjøbenhavn IV, 1: 131. 1879. Discussion. Stereophyllum is unique in the family by its short, unipapillose laminal cells. The papillae are not always obvious and may, on occasion, be lacking. Although many species have been placed in the genus, all but one have been either transferred to other genera or synonymized, leaving Stereophyllum monospecific.