Hypnum pseudostramineum Müller Hal., Bot. Zeitung (Berlin) 13: 502. 1855 (as pseudo-stramineum); Calliergidium pseudostramineum (Müller Hal.) Grout; C. pseudostramineum var. hoveyi Grout; C. pseudostramineum var. plesistramineum (Renauld) Grout; Drepanocladus pseudostramineus (Müller Hal.) G. Roth

Plants green, yellow-green, or brownish. Stems with axillary hair distal cells 1-3. Stem leaves narrowly ovate-triangular or ovate, almost straight, slightly falcate, or rarely strongly falcate, concave; margins ± entire or finely denticulate; apex obtuse, acuminate, or blunt, incurved; costa ending 2/3 -4/5 leaf length; alar region isodiametric or sometimes transversely triangular, supra-alar cells large, forming oval or rectangular region with alar cells along basal margin. Mineral-poor and acid habitats (disturbed), slightly sloping poor fens, ditches, periodically water-filled depressions; low to high elevations (0-2200 m); Greenland; B.C., Nfld. and Labr., Ont.; Alaska, Calif., Minn., Wash., Wyo.; s South America; Europe; Pacific Islands (New Zealand); Subantarctic Islands.

Warnstorfia pseudostraminea is usually readily recognizable in the field, where the species gives an impression of an intermediate between W. fluitans and Straminergon stramineum. The species, which is never red, could be confused with 1. W. fluitans or green plants of Sarmentypnum exannulatum, and the distinguishing characters of these species are given in their respective discussions. Calliergidium, in which W. pseudostraminea has been placed, is discussed under Drepanocladus (Amblystegiaceae).