Jamaican Weissia Moss

West Indian specimens of Weissia jamaicensis are distinct in the adaxial stereid band larger than the abaxial, the adaxial surface of the costa strongly bulging, and the strongly differentiated, sheathing leaf base with distinct shoulders and thick-walled medial cells bordered by thin-walled marginal cells running up the leaf in a V (as in Tortella). In the flora area, W. jamaicensis may exhibit an adaxial stereid band not as large as the abaxial band, and a poorly differentiated leaf base (as in Texas, Redfearn 30559, MO). Such specimens may be distinguished from the similar T. crispulum, however, by the sharply incurved distal leaf margins and bulging adaxial costal surface.

Leaves long-lanceolate, base strongly differentiated, rec-tangular, shoulders strong, distal laminal margins strongly and sharply incurved or inrolled, apex usually somewhat cucullate, acute or narrowly obtuse, mucro usually weak, of 1-3 cells; costa adaxial stereid band almost as large as or larger than the abaxial; distal laminal cells 8-11 µm wide. Sexual condition dioicous (archegoniate plants). Sporophytes absent in range of the flora.

Tortula jamaicensis Mitten, J. Linn. Soc., Bot. 12: 147. 1869; Trichostomum jamaicense (Mitten) A. Jaeger