Hyophiladelphus

Plants loosely cespitose 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 mid leaf, 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.

Distribution

se United States, Caribbean region and bordering areas.

Discussion

Species 1.

Hyophiladelphus has been segregated from Barbula and placed first in the Pottioideae (R. H. Zander 1995), then back into Barbuloideae (Zander 2006). Barbula sect. Agrariae Steere in Grout is an illegitimate name that has been used for this taxon. The gametophytes of this genus have a distinctive combination of broad leaves and two stereid bands in the costa.

Selected References

Zander, R. H. 1995. Phylogenetic relationships of Hyophiladelphus gen. nov. (Pottiaceae, Musci) and a perspective on the cladistic method. Bryologist 98: 363–374.

Lower Taxa

Hyophiladelphus agrarius