Plant Guide > Mosses and Lichens > Mosses > Genus Hypnum

Genus Hypnum

Genus HypnumGenus HYPNUM, Dill.

The species of the Genus Hypnum in its wider sense all agree in having the peristome double and perfect, the outer of sixteen, strong, lance-shaped, taper-pointed and densely cross-barred teeth; the inner a broad membrane divided to the middle, or about, into sixteen, keeled, yellow segments, distantly cross-barred, entire, or cleft more or less along the keel, the segments generally separated by 1 to 3 filiform divisions (cilia) cross-barred and often bearing tiny spurs on the margin.

The difference in the species will perhaps better be understood by reference to the following synopsis of the sub-genera represented by the species which follow.

Dr. Johnston in speaking of the genus Hypnum said that perhaps it formed one-fourth of the vegetable clothing of Great Britain.

The word hypnum is from the Greek for an ancient name for some sort of moss supposed to promote sleep.