Common name: Diphyscium is called 'powder gun moss' because of the way the spores are emitted in little puffs when hit by raindrops (Crum, 2004).

Taxonomy: The genus Diphyscium is the largest member of the family Diphysciaceae and includes 12 species (Schofield, 2007).

Ohio representatives: Diphyscium foliosum

Habitat: There are two species of Diphyscium in North America, D. foliosum and D. mucronifolium. Diphyscium foliosum grows on soil in forest floors and in tundras (and occasionally on rocks) throughout eastern North America. Diphyscium mucronifolium grows on humid rock surfaces (particulary sandstone) throughout the southeastern United States (Schofield, 2007).

Distribution: North, Central and South America, West Indies, Europe, Asia, Atlantic Islands, Pacific Islands and Australia (Schofield, 2007).

Gametophyte Morphology: Diphyscium is an acrocarpous moss with terminal sporophytes. The stems are unbranched and very short (Crum, 2004). The vegetative leaves are lingulate (Schofield, 2007) or lingulate-subulate (Crum, 2004) and mostly entire (Schofield, 2007). The costa is single and ends at or below the apex (Crum, 2004). The upper cells are 2-3 stratose (Crum, 2004), quadrate to isodiametric (Schofield, 2007), thick-walled and papillose or mamillose or smooth (Schofield, 2007). The lower cells are hyaline, rectangular and smooth (Schofield, 2007). The perichaetial leaves have a long, smooth or spinulose awn that is commonly longer than the blade (Schofield, 2007). The protonema are persistent and bear peltate appendages (Crum, 2004).

Sporophyte Morphology: The most distinctive feature of Diphyscium is its sporophyte. Unlike many other mosses, the seta is very short, so the ovoid-conic capsules are almost sessile (Crum, 2004) and nearly enveloped by the perichaetial leaves (Schofield, 2007). The capsules have a very narrow tip and a broad base and are thin-walled (Crum, 2004). The operculum is acute and there are 16 exostome teeth (Crum, 2004). The naked (hairless) calyptra barely covers the operculum and is conic or thimble-shaped (Crum, 2004). William C. Steere once commented that the sporophytes look like 'scarred rabbits in the grass' (Crum, 2004).

References:
Crum, H. 2004. Mosses of the Great Lakes Forest. Ann Arbor, MI: University of Michigan Herbarium.
Schofield, W.B. 2007. Diphysciaceae. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 12+ vols. New York and Oxford. Vol. 27, pp. 162-164.

Written by Aliya Donnell 2008