Coscinodon calyptratus (Hook in Drumm.) C. Jens. in Kindb.
steppe mouse-moss (coscinodon moss)

Species Account Author: Wilf Schofield
Extracted from Some Common Mosses of BC

Introduction to the Bryophytes of BC


© Bryan Kelly-McArthur     (Photo ID #86286)


E-Flora BC Static Map

Distribution of Coscinodon calyptratus
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Species Information

Species description:
Genus name referring to the irregular holes in the peristome teeth. Species name noting the large, hood-shaped calyptra.
Sporophytes frequent in spring; the sporangia are smooth when ripe.
Distinguishing characteristics:
The rounded tufts with conspicuous hair points on the leaves, the semi-arid climate restriction, and the bell­shaped calyptrae will separate this species.
Forming whitish to grayish, rounded tufts; the hair points on the leaves are conspicuous and create the grayish appearance of the tufts.
Similar Species:
Several species of Grimmia resemble this moss, but in Grimmia the calyptrae are never bell-shaped and only partially enclose the sporangium. Technical microscopic features also distinguish Cos­cinodon from Grimmia. Unfortunately species of Grimmia of similar form are frequent in the semi-arid interior. G. pulvinata, which super­ficially resembles C. calytratus, has a curved seta unlike the straight seta in Coscinodon; the sporangia are grooved when ripe in Grimmia pul­vinata, smooth in Coscinodon.


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration SourceSome Common Mosses of BC

Habitat and Range

On rock surfaces usually in open sites of semi-arid climates.
World Distribution

Confined to western North America, reaching its northern limit in the semi-arid interior of British Columbia and ex­tending southward to southern California and Arizona; predominantly at lower elevations but extending occasionally to subalpine sites.


Synonyms and Alternate Names:
Grimmia calyptrata Hook.