Entodon is a genus of pleurocarpous (mat-forming) mosses in the family Entodontaceae, order Hypnales. It was described by Carl Müller in Linnaea in 1845; the name derives from the Greek entos ("inside") and odon ("tooth"), referring to the peristome teeth, which are inserted below the mouth of the capsule.
Plants form extensive, lustrous mats, with creeping stems that are irregularly branched to subpinnate and branches that are either terete-foliate (round in cross-section) or complanate-foliate (flattened). Leaves are oblong-lanceolate to oblong-ovate and typically not plicate (pleated), with numerous quadrate to subquadrate alar cells at the leaf base. Each capsule is borne on a single seta and is yellow- to red-brown, with an exserted columella and a long-conic to obliquely rostrate operculum; a prostome is absent, and the exostome teeth range from yellow-brown to reddish.
The genus is divided into two subgenera, Entodon and Erythropus, distinguished by sporophytic characters such as seta color, the presence or absence of an annulus, and the color and ornamentation of the exostome teeth. Because these peristome features are diagnostic, species are usually identified from fertile material, though sterile plants can often be distinguished by leaf characters alone.
With roughly 70 species, Entodon has a cosmopolitan distribution, occurring across North America, Mexico, the West Indies, Central and South America, Eurasia, Africa, the Atlantic and Pacific Islands, and Australia. The genus is particularly well represented in Andean South America and East Asia.
Etymology
The genus name combines the Greek entos ("inside") and odon ("tooth"), referring to the peristome teeth, which are inserted below the mouth of the capsule.
Distribution
Entodon comprises about 70 species with a cosmopolitan distribution spanning North America, Mexico, the West Indies, Central and South America, Eurasia, Africa, the Atlantic and Pacific Islands, and Australia, and is especially well represented in Andean South America and East Asia.
Taxonomy Notes
The genus was described by Carl Müller in Linnaea (1845) and is placed in family Entodontaceae, order Hypnales. It is divided into two subgenera, Entodon and Erythropus, separated by sporophytic characters (seta color, presence/absence of an annulus, and exostome tooth color/ornamentation); species are most reliably identified from these peristome features, though sterile plants can sometimes be told apart by leaf characters.
