Diphyscium involutum Mitten
Plants dark green to brownish, somewhat glossy, tightly affixed to substratum. Stem 0.5--1 mm, erect, strongly radiculose. Leaves 0.5--5 mm, and somewhat crisped when dry,, apex acute, the most proximal leaves reduced, laminal cells smooth, margins entire. Perichaetial leaves with smooth awn, 9--12 mm, lamina at awn base lacerate but not membranaceous. Capsule narrowly ovoid, 2--3 mm long, stomata absent, mature capsule sheathed in the penicellate perichaetium, the awns extending to more than twice the length of the immersed capsule. Spores 9--12 mm.
Sporophytes infrequent, capsules mature summer. Always on somewhat shaded humid rock surfaces, especially sandstones, conglomerate and schists; 900--1000 m; Ala., Ga., Ky., N.C., Tenn., Va; se Asia (China, India, Japan, Philippines, Sri Lanka).
This is an example of an East Asian disjunctive species, and is found only as local, small populations.