Pleuridium sect. Pseudephemerum Lindberg
Stem with central strand. Leaf reflexed-recurved, lanceolate, lacking differentiated alar cells, base sheathing, cells thin-walled, aerolation lax, pellucid; costa serrulate abaxially; margins mostly serrulate at apex but occasionally to the base, doubly toothed mostly at angles acute to the long axis. Sexual condition synoicous; antheridia in axils of leaves, becoming lateral after indeterminate growth of the stem. Capsule cleistocarpous, immersed in perichaetial leaves; apiculus short, acuminate. Seta very short. Calyptra cucullate.
Species 1 (1 in the flora): North America; South America; Africa; Europe; Asia; Pacific Islands (New Zealand).
This genus is placed in the Ditrichaceae because the chromosome number of n = 13 (E. Lawton 1971) is similar to that of Ditrichum, the type genus of the family. A recent study (M. Stech 1999) supported the relationship between Pseudephemerum and Trichodon, both of the Ditrichaceae.
SELECTED REFERENCES
Lawton, E. 1971. Moss Flora of the Pacific Northwest. Nichinan. 362 pp.+ 195 plates. Nyholm, E. 1986. Illustrated Flora of Nordic Mosses, Fasc. 1. Lund. 72 pp. Stech, M. 1999. Molekulare Systematik haplolepider Laubmoose (Dicrananae, Bryopsida). Inaugural-Dissertation zur Erlangung der Doktorwürde, Freien Universität Berlin.
