Trichostomum glaucescens Hedwig, Sp. Musc. Frond., 112. 1801

Leaves 1-2.5(-3.5) mm, proximal leaves small, the distal and perichaetial leaves gradually acuminate, ± subulate from a lanceolate base; costa with a single row of guide cells, and both adaxial and abaxial stereid bands, or adaxial stereid band sometimes weak or rarely absent; lamina cells often irregularly 2-stratose towards the apex and occasionally elsewhere. Seta to 15 mm. Capsule with operculum to 1 mm. Spores 15-20(-22) µm, greenish to yellow-brown.

Capsules mature early summer-late fall. Soil on steep banks, particularly those protected by overhangs, frequent on roadsides, soil in sheltered rock crevices; moderate to high elevations; Greenland; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., Que., Yukon; Alaska, Ariz., Colo., Iowa, Mich., Minn., Nebr., N.J., N.Y.; n Eurasia; e Asia; s Africa; Pacific Islands (Hawaii, New Zealand).

The whitish to bluish coloration of the leaves is characteristic. Often thought to have been fungal or cyanobacterial in origin, the granular or thread-like surface material responsible for the glaucous coloration is a diterpene.