Monographs Details: Schlotheimia
Authority: Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)
Family:Orthotrichaceae
Scientific Name:Schlotheimia
Description:Genus Description - Plants medium-sized to large, in dense, often tomentose, usually reddish-brown mats on trees. Stems creeping, with numerous, ascending, stout, usually forked branches up to 6 c m high. Brood bodies rarely present on the leaves. Leaves imbricate, appressed to loosely appressed, erect to flexuose, often spirally-twisted around the stem when dry, ± spreadingflexuose to wide-spreading when moist, linear-lanceolate to ovate-oblong, usually acute, apiculate or long-cuspidate, sometimes rugose; margins plane to broadly reflexed, entire or serrulate in the upper half; costa strong, excurrent or ending just below the apex; upper cells small, about 6-10 µm, rounded to rhomboidal, thick-walled, usually smooth, in diagonal rows; basal cells elongate, with walls unevenly thickened, porose, sometimes sinuose, without border of thin-walled cells. Pseudautoicous (with dwarf male plants on leaves). Perichaetial leaves sometimes strongly differentiated, clasping the seta, long-lanceolate, acuminate to aristate. Setae smooth; capsules fully exserted or rarely immersed, erect, elliptic to cylindric, smooth or sometimes lightly plicate; operculum large, hemispheric, rostrate; stomata superficial, poorly developed at base of the capsule or absent; exostome teeth 16, erect or recurved, well developed, thick, linear-lanceolate, often blunt, red to brown, densely papillose and horizontally striate; endostome segments 16, opposite the exostome teeth and shorter than them, sometimes rudimentary, pale, usually vertically striate. Spores anisosporous, papillose, brown. Calyptrae mitrate, long-conic to campanulate, 4-6 lobed, smooth or papillose, not plicate, naked or hairy, usually covering the entire capsule.

Discussion:The three Mexican species of Schlotheimia are epiphytic, with occasional occurrences on rock. The genus can be easily recognized by a long-conic, smooth calyptra which is broadly 4-6 lobed at base. (All the Mexican species have naked calyptrae.) Most species (and all the Mexican ones) have smooth capsules with a well-developed peristome of 16 exostome teeth and 16 endostome segments. The spirally arranged, reddish or chestnut leaves and creeping habit are also characteristic. The elongate to linear, extremely thick-walled, nodose basal cells are unlike those of Macromitrium, which may also have elongate basal cells. Schlotheimia has no leaf border, while in Macromitrium, at least all of the Mexican species, the leaves are shortly bordered at base by hyaline, thin-walled cells.

I have not yet examined several South American types, and so some names are tentatively applied. The synonymy from the New World tropics will be extensive, but the names used for the Mexican species are quite early and will probably remain in usage.