Buxbaumia viridis (D.C.) Moug. & Nestl.

Green Bug Moss

Buxbaumiaceae

General Description: An inconspicuous moss. It virtually lacks a leafy plant and the most conspicuous part is the green, felty protonema. The tiny capsule and its stalk (seta) are visible to the naked eye upon close examination. The dark brown seta is under 1 cm long. The capsule is 5-6 x 2.3-3 mm, ovoid, flattened on top and rounded beneath like a rowboat, green when young, but maturing to a yellow-brown color, and not glossy. The capsule is inclined to the side when mature. To dehisce the spores, the cuticle on the top side of the capsule splits longitudinally and curls back toward the edges of the capsule.

Field Identification Tips: Tiny mosses comprised of a single capsule on a stalk with no evident green leaves identifies the genus. Positive species identification requires mature capsules.

Phenology: The sporophyte appears in late spring or early summer and lasts a relatively short time.

Similar Species: Buxbaumia aphylla has a brown, glossy capsule, and typically occurs on nutrient poor soil in open areas. Plants of B. viridis cannot be separated from the immature green capsules of B. piperi, which also typically occurs on rotten logs. For B. viridis, the mature capsule splits longitudinally and peels back toward the edges of the capsule, while the cuticle rolls back from the mouth in both B. piperi and B. aphylla.

Habitat: Rotten logs, peaty soil and humus, in shady, humid coniferous forests, from low to subalpine elevations. Usually on rotten logs in an advanced stage of decay.

Global distribution: Interruptedly circumboreal; it occurs in all provinces and states in the Pacific Northwest region, and also is found in eastern North America.

Idaho Distribution: This species is known from Kootenai County in the Panhandle region, and from Latah, Clearwater, Idaho, and Valley counties to the south.

References:

Christy, J. A., and D. H. Wagner. 1996. Guide for the identification of rare, threatened or sensitive bryophytes in the range of the northern spotted owl, western Washington, western Oregon, and northwestern California. Printed by the Bureau of Land Management, Oregon-Washington State Office, Portland, OR.

Lawton, E. 1971. Moss flora of the Pacific Northwest. The Hattori Botanical Laboratory, Nichinan, Miyazaki, Japan. 362 pp., plus plates.