Monographs Details: Crossidium crassinervium (De Not.) Jur.
Authority: Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part One: Sphagnales to Bryales. Mem. New York Bot. Gard. 69 (1)
Family:Pottiaceae
Description:Species Description - Plants 2-5 mm high. Leaves up to 1.3 mm long, broadly-lanceolate, oblong-ovate, or lingulate, obtuse, rounded, or emarginate, smoothly hair-pointed; margins entire, reflexed or revolute nearly to the apex; costa in section showing 2-5 layers of stereids, the green filaments 2-12 cells long, ending in a conic cell with 2 or more weak papillae; upper and midleaf cells 7-22 µm, subquadrate to short-rectangular, smooth; basal cells up to 58 p m long, but often much shorter (as little as 7 µm). Dioicous or cladautoicous. Perichaetial leaves not much differentiated, obtuse, clasping, plane-margined. Setae 6-13 mm long; capsules about 1-2.2 mm long, dark-red, ovoid-cylindric; annulus in 2 rows; operculum 0.6-1 mm long, conic-rostrate, erect or inclined; peristome 400-900 µm long. Spores 9-15 µm, nearly smooth to conspicuously papillose.

Discussion:

Fig. 273d-h

C. crassinervium (De Not.) Jur., Laubm. Osterr.-Ungarn 128. 1882.

Tortula crassinervia De Not., Mem. Reale Accad. Sci. Torino 40:303. 1838.

Crossidium desertorum Holz. & Bartr., Bryologist 26: 72. 1923.

C. erosum Holz. & Bartr., Bryologist 27: 3. 1924.

This highly variable species may be autoicous or dioicous. Essential features include smooth leaf cells and generally long costal filaments ending in a narrow, conic, weakly 2-4-papillose cell. T h e filaments, up to 12 cells long in contrast to the 1-6 cells in other Mexican species, give the appearance of a thick costa.

Distribution:India Asia| Algeria Africa| Chad Africa| Europe| Mexico North America| United States of America North America| Canary Islands of Spain Africa|