Stephen L. Timme
Hypnum subsect. Vesicularia J. K. A. Müller
Plants small to medium-sized, generally pale- to yellowish-green, sometimes dark-green, often in shiny mats. Stems creeping, freely branching, irregular to pinnate, with or without a central strand. Branches horizontal, simple, somewhat flattened, pseudoparaphyllia linear to foliose. Leaves dimorphic, ventral leaves generally smaller than the dorsal leaves, ± appressed, lanceolate to generally acuminate; dorsal leaves spreading to secund, somewhat asymmetric, ovate-lanceolate, oblong-lanceolate, ovate-lanceolate to oblong-ovate, apex acute or short- to long-acuminate, sometimes apiculate, margins entire or serrulate toward the apex; costa short and double or lacking. Sexual condition generally autoicous; perichaetial leaves erect, subulate from an ovoid, oblong-ovoid, or oblong-ovate base, margins entire, serrulate to somewhat denticulate. Seta elongate, flexuose, smooth, reddish or reddish orange to yellow-orange, curved just proximal to the capsule. Capsule horizontal to pendent, ovoid to oblong-ovoid, ± asymmetric, sometimes constricted proximal to the mouth when dry, annulus differentiated, exothecial cells quadrate to rectangular, thin-walled, often collenchymatous, operculum apiculate to short-rostrate, peristome double, teeth lanceolate, cross-striolate, tubeculate, papillose distally, endostome with a high basal membrane, segments keeled, cilia present, generally in groups of 1--3, stomata at the extreme base of the capsule. Calyptra smooth, cucullate. Spores spherical, finely papillose to nearly smooth.
Species 175--190 (1 in the flora). Southeastern U.S.A., Mexico, West Indies, Central America (Guatemala), n South America, Africa (including Madagascar), Asia (India, Japan, Philippines), Indian Ocean Islands, Pacific Islands, Australia.
This is a poorly studied genus and many of its species will undoubtedly be synonymous with other taxa when the group is studied on a worldwide basis.
SELECTED REFERENCE
Buck, W. R., 1984. Taxonomic and nomenclatural notes on West Indian Hypnaceae. Brittonia 36: 178--183. Salmon, E. S. 1904. A revision of some species of Ectropothecium. Bull. Torrey Bot. Club 31: 309--324.
