Trichostomum molariforme sp. nov. and Atractylocarpus stenocarpus (Wils. in Seem.) comb. nov.

Abstract

Trichostomum molariforme is newly described from Mexico, the West Indies and Louisiana in the U.S.A. Trichostomum stenocarpum Wils. in Seem. is transferred to the genus Atractylocarpus, being an earlier name for A. costaricensis (C. Muell.) Bartr. In a treatment of Barbula in North America (Zander 1979), I assigned certain long- leaved, West Indian specimens with narrow adaxial laminal grooves, very thick papillae and short, straight peristomes to B. indica (Hook.) Spreng. This species, indeed, may have rather long leaves, somewhat thickened laminal papillae and short, straight peri- stomes; however, further study has convinced me that the above specimens represent a new taxon distinguished from B. indica by the leaves often oblong-linear with the leaf base not widened (except in perichaetial leaves), the upper laminal cells often irregularly protuberant on either side of the lamina, the upper laminal papillae forming thick caps reminiscent of the cusps of molar teeth, and the peristome teeth irregularly ligulate and smooth, not filamentous and spiculose. The new species is assigned to Trichostomum s. str. on the'basis of the plane leaf margins, flat, multiplex laminal papillae, and plate-like peristome teeth.