Didymodon laevigatus (Mitt.) Zand., Phytologia 41: 29. 1978.

Tortula laevigatus Mitt., J. Linn. Soc., Bot. 12: 160. 1869. Barbula laevigata (Mitt.) Jaeg., Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1871–72: 426. 1873. Protologue: Ecuador.  Andes Quitenses in monte Cordovasto (11,000 ped.) Spruce, n. 199; Chimborazo (10,000 ped.), Spruce, n. 200. Lectotype (Steere 1948): Spruce 199. 

Plants medium- or robust-sized, reddish yellow above, brown below, in tufts to 30 mm high. Stems red, erect, sparsely and irregularly branched, sclerodermis and central strand present; rhizoids sparse, at base of stems. Axillary hairs 3–5 cells long, basal cell brown. Leaves 2.0–3.3 mm long, lanceolate from a broadly ovate base, erect and somewhat clasping at base, erect-incurved to erect-contorted when dry, erect-spreading when wet, keeled and somewhat grooved along the costa on ventral surface; apices sharply acute to subulate; lamina unistratose or occasionally bistratose along the margins; margins entire, recurved to  revolute below, plane at times recurved above; costa filling the apex and stoutly excurrent, surface ventral cells elongate, guide cells well-developed, dorsal and ventral stereid bands present, at times poorly developed, ventral and dorsal surface cells small, thick-walled; upper and basal cells smooth, weakly differentiated, upper cells very thick-walled, round, oblate or oblong, 4–10 x 6–12 μm, basal cells long- to short-rectangular, thick-walled, 17–56 x 8–10 μm, basal marginal cells subquadrate, alar cells not differentiated. Dioicous. Perichaetia terminal. Sporophytes unknown in Central America, description based on South American plants. Setae smooth, 12–20 mm long, red. Capsules long-cylindrical, erect, 2.0–3.0 mm long, smooth; exothecial cells long-rectangular, firm-walled; stomata in neck; opercula erect, long-conic, 1.5–2 mm long; annuli well-developed; peristome red, basal membrane low, teeth 1.5 mm long, spirally twisted. Spores 16 μm, smooth. Calyptrae not seen.