Monographs Details: Didymodon fallax (Hedw.) Zander var. fallax
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 green to red-brown above, brown to red-brown below. Stems irregularly branched, up to 20 m m high. Leaves when dry erect or weakly spreading, when moist spreading to widely reflexed, keeled, 1.2-2 mm long, ovate-triangular to lanceolate, acute, the base scarcely differentiated to ovate, occasionally ± auriculate, narrowly to broadly decurrent; costa shortly excurrent into an often papillose apiculus, covered ventrally by short-rectangular or elongate cells and dorsally by quadrate cells, the ventral stereids few or none, the dorsal band reduced or lacking, rarely strong; upper cells ± rounded, hexagonal or rhombic, (5—)8—11 µm and 1-1.5:1, with papillae lacking or simple, solid, with 1-3 centered on the lumen on both surfaces, occasionally bifid to trifid; basal cells not or weakly differentiated and quadrate to short-rectangular. Setae 6-12 mm long; capsules 1.2-1.5 mm long, cylindric to ellipsoidal; operculum 1.2-1.3 mm long, longconic, with cells in straight or once-twisted rows; peristome divisions 32, linear, 275-1100 µm long, yellow to orange-yellow, densely papillose to weakly spiculose, erect or oncetwisted counterclockwise. Spores 7-9 µm, weakly papillose.

Discussion:

Fig. 229

D. fallax (Hedw.) Zand., Phytologia 41: 28. 1978.

Barbula fallax Hedw., Sp. Muse. 120. 1801.

The elongate cells of the ventral surface of the costa are characteristic, but care should be taken to distinguish sterile plants from Hymenostylium recurvirostrum (which usually has enlarged, rhombic median laminal cells) and Didymodon tophaceus (which has broadly acute or often blunt or rounded leaf apices).

Distribution:Morocco Africa| Algeria Africa| Libya Africa| Tunisia Africa| Egypt Africa| Europe| United States of America North America| Canada North America| Mexico North America|