Trichostomopsis Card., Rev. Bryol. 36: 73. 1909.
Barbula sec. Asteriscium C. Müll., Linnaea 42: 342. 1872. Asteriscium (C. Müll.) Hilp., Beih. Bot. Centralbl. 50(3): 618. 1935.
Plants small, caespitose. Stems erect, sparsely and irregularly branched, hyalodermis and central strand present; rhizoids sparse. Axillary hairs with brown basal cell. Leaves oblong, ovate-lanceolate to lanceolate, incurved-contorted when dry, channeled above on ventral surface; apices broadly acute; margins bistratose above, usually reflexed; costae subpercurrent to short-excurrent, surface ventral cells quadrate, guide cells and single (dorsal) stereid cells present, ventral surface layer enlarged, bulging, papillose; upper and basal cells differentiated, upper cells rounded to short-rectangular, firm-walled, pluripapillose, at times with c-shaped papillae, basal cells lax, hyaline, smooth, alar cells not differentiated. Dioicous. Perichaetia and perigonia terminal. Setae smooth, elongate. Capsules cylindrical; exothecial cells short-rectangular, firm-walled; stomata in neck; opercula erect, long-rostrate; annuli vesiculose; peristome teeth short, straight or slightly twisted, basal membrane low. Spores smooth. Calyptrae cucullate.