9. Pseudephemerum (Lindberg) I. Hagen, Kongel. Norske Vidensk. Selsk. Skr. (Trondheim). 1910(1): 45. 1910.
[Greek pseud-, false or resembling, and genus Ephemerum]
Kwok Leung Yip
Pleuridium sect. Pseudephemerum Lindberg, Öfvers. Kongl. Vetensk.-Akad. Förh. 21: 583. 1865
Plants gregarious to loosely tufted, yellow-green. Stem 0.04-0.2 cm, branched, rhizoids sparse. Leaf reflexed-recurved, lanceolate with sheathing base, margins serrulate at apex, occasionally to the base, doubly toothed mostly at angles acute to the long axis; costa thin and narrow, subpercurrent, serrulate abaxially, with a central stereid band, basal cells large, rectangular, distal cells rhombic, smooth. Sexual condition synoicous; antheridia in axils of leaves, becoming lateral after indeterminate growth of the stem. Seta very short, erect. Capsule cleistocarpous, immersed. Calyptra cucullate. Spores globose, papillose.
Species 1: North America, Mexico, South America, Europe, Asia, Africa, Pacific Islands (New Zealand), Australia.
This genus is placed in the Ditrichaceae because the chromosome number of n = 13 (E. Lawton 1971) is essentially that of Ditrichum, the type genus of the family. A recent study (M. Stech, unpubl.) supported the relationship between Pseudephemerum and Trichodon, both of the Ditrichaceae.