Linnaea 18: 704. 1845.
Plants medium-sized to moderately large, in extensive mats, lustrous. Stems creeping (spreading to ascending in E. concinnus), irregularly branched to subpinnate, branches relatively short, terete- or complanate-foliate. Leaves oblong-lanceolate to oblong-ovate, not plicate (slightly plicate in E. brevisetus); base not decurrent; alar cells quadrate to subquadrate; laminal cells straight to ± flexuose; basal cells shorter, walls usually porose. Seta single. Capsule yellow- to red-brown; columella exserted; operculum long-conic to obliquely rostrate; prostome absent; exostome teeth yellow-brown to reddish; endostome basal membrane low, segments linear, as long as or shorter than exostome teeth, rarely rudimentary.
North America, Mexico, West Indies, Central America, South America, Eurasia, Africa, Atlantic Islands, Pacific Islands, Australia.
Species ca. 70 (10 in the flora).
Plants of Entodon are characterized as flattened or terete pleurocarpous mosses with concave leaves and a weak double costa. The alar cells are quadrate and numerous. The two subgenera, Entodon and Erythropus, are separated on sporophytic characters, specifically the color of the seta, the presence or absence of an annulus, and the color and ornamentation of the exostome teeth. The genus is well represented in Andean South America and East Asia. Species are often best identified using exostomial ornamentation, but sterile plants can be identified from leaf characters.
|1||Leaf apices rounded-obtuse; alar cells 2- or 3-stratose; sexual condition dioicous.||Entodon concinnus|
|1||Leaf apices acute, acuminate, apiculate, or occasionally obtuse; alar cells 1-stratose; sexual condition autoicous||> 2|
|2||Branches terete-foliate||> 3|
|2||Branches complanate-foliate||> 6|
|3||Setae yellow; leaf apices slender acuminate.||Entodon brevisetus|
|3||Setae reddish; leaf apices not slender acuminate||> 4|
|4||Exostome teeth papillose proximally; sw North America.||Entodon beyrichii|
|4||Exostome teeth ± smooth or striolate proximally; e North America||> 5|
|5||Exostome teeth ± smooth proximally; leaves oblong-ovate to elliptic; apices abruptly acute to apiculate.||Entodon seductrix|
|5||Exostome teeth cross striolate proximally; leaves oblong-ovate; apices acute to gradually short-acuminate.||Entodon sullivantii|
|6||Setae yellow||> 7|
|6||Setae reddish||> 8|
|7||Exostome teeth with internal surface striate; leaves widest near insertion; se United States.||Entodon macropodus|
|7||Exostome teeth with internal surface papillose to smooth; leaves widest at 1/3 leaf length; South Carolina.||Entodon hampeanus|
|8||Exostome teeth cross striolate; annulus not differentiated.||Entodon schleicheri|
|8||Exostome teeth papillose; annulus differentiated||> 9|
|9||Leaf apices gradually acute; margins serrulate and often notched distally.||Entodon cladorrhizans|
|9||Leaf apices broadly acute; margins entire to subentire or with 1 or 2 teeth at extreme apex.||Entodon challengeri|