Craspedophyllum mucronifolium

Craspedophyllum mucronifolium (Hook. & Grev.)
Grout, comb. nov.
Orthotrichum mucronifolium Hook. & Grev. Edinb. Jour. Sci, 1: 116. 1824. Macromitrium obtusum Mitt. Jour. Linn. Soc. 12: 201. 1869. , Micromitrium mucronifolium Grout, Bryologist 47: 3, 1944.
Plants in wide, dense mats, dark green, almost black except at the tips of stems and branches; secondary stems short, 3-5 mm. long; leaves of the main stem oblong-lanceolate, acuminate, not mucronate, their costa excurrent; leaves of the secondary stems crowded, strongly twisted spirally around the stem when dry, widely spreading when moist, 1-1.5 mm. long, concave, Ungulate, short-apiculate, more or less plicate longitudinally but not undulate nor transversely wrinkled above, the margins plane and entire; costa strong, extending into the mucro or ending just below it; upper leaf-cells rounded-hexagonal or irregular, incrassate, more or less mammillose or bulging, 7-9 M in diameter, the marginal smaller; at the basal margins a few narrowly linear cells, in the main portion of the base only a few cells at the insertion noticeably elongate and colored; autoicous; seta 3-5 mm. long, smooth; capsules obovoid, whitish when old the urn about 1.5 X 1 mm., smooth or slightly wrinkled at the base when dry and empty but not contracted below the mouth; calyptra narrowly conical, covering the capsule to the base, smooth; exothecial cells thinwalled, short-rectangular to oblong-hexagonal, with a few rows of small, rounded, dark-colored cells around the mouth; stomata in the narrow neck; peristome lacking or represented by an inconspicuous low membrane; spores maturing in summer.
Type locality: St. Vincent Island.
Distribution: On the bark of shrubs and trees, especially on the upper side of horizontal branches; Florida; Mexico; Central America; the West Indies.