E-Flora BC: Electronic Atlas of the Flora of British Columbia

Species description:
Genus name meaning "the rhizoid-bearing Mnium" in reference to the numerous rhizoids on the stems of many species. Species name indicating that the stems of this species are usually smooth (or without rhizoids).

Reproduction:
Sporophytes frequent, pale brown when mature, ma­turing in spring. Male plants in separate colonies or intermixed with sporophyte-bearing shoots, the male heads flower-like, and with the mass of antheridia turning red-brown when sperms have been released.

Comments:
Sometimes called Mnium glabrescens, a synonym.

Distinguishing characteristics:
he elliptic leaves that lack any suggestion of marginal teeth but possess a distinctive differentiated margin, the rosette-like apex of the male shoot, and the usual habitat on rotten logs in forest are useful features.

Habit:
Forming relatively short, loose turfs of dark green to pale green plants tightly affixed to the substratum by reddish-brown basal rhizoids. The substratum in early colonization often matted with red rhizoids from which leafy plants arise.

Similar Species:
R. gracile and R. pseudopunctatum are both peat land species and less than half the size of R. glabrescens. R. magnifolium is also a species of wet sites, especially springy or seepage areas, and the stems are heavily clothed with a mat of rhizoids (R. glabrescens has few stem rhizoids). R. nudum is a terrestrial species of sub alpine to alpine sites and the leaves are nearly circular in outline (rather than elliptic, as in R. glabrescens). When dry, R. nudum leaves are somewhat opalescent glossy and are little changed in form (in R. glabrescens leaves are dull, dark green and contorted when dry). R. punctatum is difficult to distin­guish from R. glabrescens on field characters although the older stems of R. puuctatum tend to be red-brown rather than nearly black as in R. glabrescens.