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

Species description:
Genus name meaning "the appearance of Rhytidium", which it resembles superficially. Species name denoting that it is very large.

Reproduction:
Sporophytes occasional, maturing in late autumn, red ­brown when mature.

Distinguishing characteristics:
The coarse plants, usually of sub alpine forest floors, plus the wrinkled surface of the falcate-secund leaves and the soft, not brittle, texture of the plants are useful features.

Habit:
Forming mats of irregular branching, pale brownish-green, inter-tangled plants that creep over the substratum.

Similar Species:
Rhytidium rugosum is superficially similar to Rhytidiopsis robusta but the leaves have a single midrib rather than double as in Rhytidiopsis. Branching in Rhytidium is usually regular, at least in some plants, while in Rhytidiopsis branching is very irregular. Rhytidium usually occurs in dry, open sites while Rhytidiopsis is a forest species, reaching great abundance in humid, subalpine conifer forests. See also note under Rhytidiadelphus triquetrus.