Monographs Details: Haplocladium
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 rather small to medium-sized, in loose, dull, yellowish, brownish, or light- to dark-green mats. Stems prostrate, subpinnately branched; branches spreading or ascending; paraphyllia few to abundant, especially on stems, polymorphous, not papillose. Stem and branch leaves somewhat differentiated, erect to somewhat incurved and sometimes subsecund when dry, erect-spreading to spreading when moist. Stem leaves often biphcate, ovate, short- to long-acuminate; margins plane or revolute below; costa extending well into the acumen to excurrent, often flexuose above; cells irregularly rounded or subquadrate to rhombic, firm-walled, unipapillose at back, often at upper ends. Branch leaves smaller and narrower, ending in a sharp, unipapillose cell. Autoicous. Perichaetial leaves pale, erect or ± spreading, elongate, narrowly long-acuminate from a lanceolate base. Setae elongate, smooth, reddish; capsules strongly inclined to horizontal, curved and constricted below the mouth when dry, oblong-cylindric; annulus well developed; operculum conic, acute to short-rostrate; peristome teeth yellow or yellow-brown; endostome with well-developed, nodose or appendiculate cilia in groups of 1-3. Calyptrae naked.
The genus approaches Thuidium in pinnate branching and presence of paraphylha, but the branch leaves end in a sharp, singly papillose cell, and the cells of the paraphyllia are smooth. Both genera have perfect, hypnoid peristomes.