Monographs Details: Hygrohypnum
Authority: Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)
Description:Genus Description - Plants slender to moderately robust, in green, yellow, or red-gold, dense mats, sometimes shiny. Stems creeping, often denuded with age, irregularly branched. Leaves generally crowded, imbricate to spreading, often secund, concave (sometimes strongly so and ± cucullate at apex), smooth or weakly plicate, oblong-lanceolate and acuminate or broadly oblong-ovate to subcircular and blunt to rounded or abmptly short-pointed at the apex; margins erect (or sometimes incurved above), entire or sermlate; costa often variable on the same plants, generally unequally forked and usually short and weak, rarely single and sometimes nearly percurrent; cells smooth, linear-flexuous, often short and rhombic at the extreme apex, mostly yellow or orange but otherwise scarcely differentiated at the middle ofthe insertion; alar cells subquadrate or oblong, hyaline or colored, sometimes inflated in small, well-marked groups. Perichaetial leaves erect, elongate, generally striate, with costa short, single or forked.
The plants grow on wet rocks in or along streams. The leaves, broad and shortly pointed to rounded-obtuse, are concave and sometimes cucullate. The variability of the costa, from one species to another and even from one leaf to another on the same plant, is a curious attribute ofthe genus. The capsules are short, broad, and not much curved, as in the Brachytheciaceae, but the yellow-brown peristome teeth, wet habitats, and commonly double costae are indicative of a relationship to the Amblystegiaceae.