ERIOPHORUM (from erion, wool, and phoreo, to bear; heads cottony). Cotton Grass. Including Trichophorum. ORD. Cyperaceae. A genus (confined to North temperate and Arctic regions) of about a dozen species of pretty bog plants, closely allied to Scirpus, but differing from it in that the hypogynous bristles, as the flowering advances, protrude to a great length beyond the spikelets, forming silky-cottony tufts, whence the common name. They can be naturalised with great success by the margins of ponds, &c., or in the boggy spots of the wild garden. ERIOPHORUM alpinum (alpine). This plant resembles Scirpus caespitosus, with the exception of having long bristles. Northern hemisphere (probably now extinct in Britain). ERIOPHORUM vaginatum (sheathed). fl., spikelet solitary, terminal, ovoid, six to eight lines long, deep olive-green; hypogynous bristles numerous to each flower, forming cottony tufts, nearly globular. Stems tufted, 1ft. high, or more, covered at the base with a few loose ragged sheaths, one of which bears linear, almost subulate leaves. Northern hemisphere (Britain, but especially abundant in Scotland and Ireland).