Macromitrium involutifolium subsp. involutifolium

Pseudautoicous. Asexual propagules absent. Mats on trees or rocks, dark green to olive-green, to 10 mm tall. Stem red-brown or black, tomentose with brown or red-brown rhizoids. Branch leaves erect-incurved when moist, loosely erect with upper portion strongly inrolled, not funiculate when dry, narrowly lanceolate to ligulate, 1.7–2.8 mm long, 0.3–0.5 mm wide; apex acute; costa excurrent as a mucro; margin entire, plane or slightly reflexed, without a border; laminal cells in apical half rounded, 5–15 μm long, 10–14 μm wide, smooth or rarely with 3–4 papillae; basal laminal cells rectangular, to 70 μm long, 5–10 μm wide, smooth or sometimes with a conic papilla. Seta 1.5–5 mm long, yellowish, twisted clockwise. Calyptra with dense straight hairs. Capsules erect, cylindric to ellipsoid, 1.8–2.5 mm long, straight, yellowish to red-brown, rim erect. Peristome single; exostome teeth 16, erect. Operculum rostrate, c. 0.5 mm long.