Plants small to large, green, yellow-green, yellowish, or brownish. Stems sparsely and irregularly branched to ± pinnate, ± in one plane; hyalodermis absent, central strand present; paraphyllia absent; rhizoids or rhizoid initials on stem or abaxial costa insertion, rarely forming tomentum, slightly or occasionally strongly branched, smooth; axillary hair distal cells 1-3, hyaline. Stem leaves erect-spreading, spreading, or sometimes squarrose, straight or falcate, ovate or broadly so, ovate-lanceolate, triangular, rounded-triangular, or cordate, not plicate, 0.9-6.4 × 0.4-1.6 mm; base not or hardly decurrent (narrowly decurrent in D. cardotii); margins plane, entire, slightly sinuate, or slightly denticulate, limbidia absent; apex long-acuminate to acute, ; costa double and short, single and long, or sometimes excurrent; alar cells differentiated, short-rectangular to short-linear, strongly inflated, hyaline, , region distinct, transversely triangular or ± quadrate, ; medial laminal cells linear; marginal cells 1-stratose. Sexual condition autoicous [synoicous] or dioicous. Capsule horizontal, cylindric, curved; peristome perfect; exostome margins entire or slightly dentate distally; endostome cilia 2-4, well developed, nodose or distally sometimes appendiculate. Spores 11-32 µm.
SELECTED REFERENCES Hedenas, L. 1996. On the interdependence of some leaf characters within the Drepanocladus aduncus-polycarpus complex. J. Bryol. 19: 311-324. Hedenas, L. 1997b. The Drepanocladus s. str. species with excurrent costae (Amblystegiaceae). Nova Hedwigia 64: 535-547. Hedenas, L. 1998. An overview of the Drepanocladus sendtneri complex. J. Bryol. 20: 83-102. Janssens, J. A. 1983. Past and extant distribution of Drepanocladus in North America, with notes on the differentiation of fossil fragments. J. Hattori Bot. Lab. 54: 251-298. Wynne, F. E. 1944b. Studies in Drepanocladus. IV. Taxonomy. Bryologist 47: 147-189. Zarnowiec, J. T. 2001. A Taxonomic Monograph of the Drepanocladus aduncus Group (Bryopsida: Amblystegiaceae). Bielsko-Biala.