Syntrichia fragilis (Tayl.) Ochyra, Fragm. Florist. Geobot. 37: 212. 1992.
Tortula fragilis Tayl., London J. Bot. 6: 333. 1847. Protologue: Ecuador. On Pichincha; Prof. W. Jameson. Nov. 1846.
Plants medium-sized, forming tufts or mats, reddish green to green above, brownish green to brown below, saxicolous, corticolous, or terricolous. Stems 5–20 mm high, irregularly branched, central strand weakly developed, epidermal cells thin-walled, not distinctly differentiated; rhizoids scattered on stem, smooth. Axillary hairs 6–8 cells long, all hyaline. Leaves 2–3.5 mm long, oblong-lingulate, to spathulate, erect at base, appressed, flexuose-twisted to spirally twisted around stem when dry, wide-spreading when wet; apices acute to obtuse, mucronate; lamina unistratose, fragile; margins entire or lightly crenulate, plane above, revolute at base; costa narrow, percurrent to short excurrent, surface cells quadrate, papillose on both surfaces, guide cells and single (dorsal) stereid band well-developed, ventral surface layer of enlarged, papillose cells present; upper cells irregularly quadrate, oblate, or short-rectangular, 6–14 x 3–10 μm, firm-walled, densely and thickly pluripapillose with branched or c-shaped papilla, marginal cells at times differentiated as a border of brownish, thicker-walled cells, basal cells abruptly differentiated, rectangular, thin-walled, hyaline, smooth, 50–110 x 20–30 μm, becoming short-rectangular and firm-walled near the margins, alar cells not differentiated. Dioicous. Perichaetia and perigonia terminal. Setae smooth, 10–15 mm long, reddish brown. Capsules cylindric, erect, 2–4 mm long, smooth, reddish brown; exothecial cells long-rectangular, firm-walled; stomata in neck; opercula rostrate, beak erect, 1.5–1.8 mm long; annuli of 2–3 rows of vesiculose cells; peristome teeth yellow-brown, 1.2–1.5 mm long, filaments papillose, erect to twisted 1/2 turn, basal membrane short. Spores 15–22 μm, granulate. Calyptrae cucullate, smooth, 3 mm long.