Genus CeratodonGenus CERATODON, Brid.
The species of this genus are small erect plants growing in bright or dark-green cushions on soil or in the crevices of rocks.
The leaves are lance-shaped and keeled, with entire or toothed margins, and a vein extending to or beyond the apex.
The mature spore-cases are long-egg-shaped, erect or slightly arched, with a short neck. They are dark or pale-red with winered or yellow pedicels, and short-beaked, conical lids, becoming deeply furrowed, inclined, and contracted below the mouth when old.
There is but one row of teeth, each tooth being cleft into two equal and strongly jointed segments, which suggest the generic name Ceratodon, a compound of two Greek words; a horn and; a tooth.
The two characteristics by which one may feel sure that his moss is a horn-tooth, are the cleft teeth and the shape and grooving of the spore-cases.
There are eighteen species in all, one common in North America.
Purple Horn Tooth Moss