Richard H. Zander
Barbula subg. Hyophiladelphus (J. K. A. Müller) R. H. Zander
Plants loosely caespitose to gregarious, blackish green distally, brown proximally. Stems very short, to 0.2 cm, central strand present, sclerodermis absent, hyalodermis absent; axillary hairs 2--3 cells long, all hyaline. Stem leaves appressed when dry, weakly spreading when moist to rosulate, oblong, 1.2--2 mm, elliptic or spathulate, distal lamina broadly channeled to deeply concave, margins plane, entire; apex broadly acute; base oblong or not differentiated, alar region often enlarged and bulging; costa percurrent to shortly and stoutly excurrent, adaxial superficial cells elongate, (2--)4 rows of cells across costa adaxially at midleaf, costal transverse section oval to circular, two stereid bands present, adaxially small, epidermis differentiated adaxially, present or occasionally absent abaxially, guide cells 2 in 1 layer, hydroid strand absent, distal laminal cells subquadrate to subrectangular, occasionally rhomboid, walls thin, occasionally evenly thickened, superficially adaxially bulging, abaxially flat, (8--)11--13(--15) mm wide, 1--2:1; papillae absent; proximal cells differentiated across leaf in a small area or up to 1/3 leaf length, alar cells often sharply bulging, proximal cells rectangular and curved. Specialized asexual reproduction absent. Sexual condition dioicous. Perichaetia terminal, interior leaves ovate, weakly sheathing in proximal 1/2--2/3, proximal cells rhomboid. Seta 0.4--1 cm. Theca (0.3--)1--1.7 mm, cylindric to elliptic, annulus deciduous, revoluble, 1--2 rows of strongly vesiculose cells; peristome teeth of 32 narrow rami, filamentous, 500--1200 µm, twisted counterclockwise, operculum long-conic. Calyptra cucullate. Spores small, 9--11 µm. Distal laminal KOH color reaction strongly yellow orange, occasionally medium orange.
Species 1 (1 in the flora): known only from the Caribbean region and bordering areas.
This genus has been segregated from Barbula and placed in the Pottioideae (R. H. Zander 1995). The gametophytes have a distinctive combination of broad leaves and two stereid bands in the costa.
SELECTED REFERENCES
Zander, R. H. 1993. Genera of the Pottiaceae: Mosses of Harsh Environments. Bull. Buffalo Soc. Nat. Sci. 32. Zander, R. H. 1995. Phylogenetic relationships of Hyophiladelphus gen. nov. (Pottiaceae, Musci) and a perspective on the cladistic method. Bryologist 98: 363--374.1995.
OTHER REFERENCES
Breen, R. S. 1963. Mosses of Florida. Gainesville.
Reese, W. D. 1984. Mosses of the Gulf South. Baton Rouge.
