• Webster's Revised Unabridged Dictionary
    • n Hypnum (Bot) The largest genus of true mosses; feather moss.
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Century Dictionary and Cyclopedia
    • n hypnum The largest genus of mosses, embracing 30 or more subgenera that have by many authors been considered as genera. It belongs to the series Pleurocarpi, in which the fruit is lateral, and sessile upon the stems or branches, and the sexual organs are in axillary buds. The capsule is solid, long-pedicellate, cernuous or horizontal, more or less incurved. not pendent, and very rarely erect and regular. The peristome is double, the outer consisting of 10 strong, densely articulate, lanceolate-acuminate teeth, the inner of a broad membrane divided to (or nearly to) the middle into 16 carinate yellow segments, alternating with the outer teeth and with intermediate cilia, which are either solitary or in groups of 2 or 3. The genus is widely distributed in all parts of the world. There are 200 North American and 90 or more British species. The genus is frequently found in a fossil state, about 30 extinct species having been described from the Miocene and Quaternary deposits of Europe, and from the arctic regions. One species (H. Haydenii) occurs in the Green River group (Eocene) of Colorado.
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Chambers's Twentieth Century Dictionary
    • n Hypnum hip′num the largest genus of mosses, order Bryineæ, having archegonia and capsules borne on special lateral branches.
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Webster's Revised Unabridged Dictionary
NL., fr. Gr. moss


In literature:

Beautiful hypnum carpets bordered with ferns are spread beneath them, violets too, and a few daisies.
"My First Summer in the Sierra" by John Muir
The double peristome of a Hypnum.
"The Elements of Botany" by Asa Gray