1. Cyclodictyon Mitten, J. Proc. Linn. Soc., Bot. 7: 163. 1863. • [Greek kyklos, circle, and diktyon, net, alluding to large laminal cells].
Plants small to medium-sized, in soft, delicate, thin, flattened mats, white to pale green or bluish, glaucous. Stems irregularly branched to pinnate; hyalodermis present. Leaves complanate, shriveled or ± crisped when dry, ovate to broadly ovate, asymmetric, dorsiventral and lateral leaves similar in shape; margins plane or occasionally narrowly recurved, entire or serrulate distally; apex short-acuminate; costa 2/3-3/4 leaf length, ending in base of acumen, divergent, distal abaxial surface smooth; laminal cells hexagonal or oblong-hexagonal, lax, smooth; marginal cells forming border. Specialized asexual reproduction unknown. Sexual condition synoicous and autoicous; perichaetial leaf apex short- to long-acuminate. Seta dark red, smooth. Capsule inclined, horizontal, or pendulous, oblong-cylindric; annulus narrow; operculum straight, narrowly long-rostrate. Calyptra mitrate, base short-lobed, smooth.
Species ca. 90 (1 in the flora): se United States, Mexico, West Indies, Bermuda, Central America, South America, Eurasia, Africa, Pacific Islands.
Species of Cyclodictyon occur mostly in the Neotropics, though they are widespread in tropical Africa. Their habitat is moist to wet soil, humus, leaf litter, infrequently on rock, occasionally epiphytic, from near sea level to 3900 m (S. R. Gradstein et al. 2001).