Flora of North America species comparison

Grimmia ramondii occurs near sea level in arctic areas and along the West Coast. In the latter region, however, it is more common in mid-elevation montane sites and may also be found above the tree line. It differs from most Grimmia species by its lack of awns, winged costa, and tall, loose growth form. At first sight, G. ramondii has the habit of a Racomitrium. However, the sporophyte has an arcuate rather than straight seta, and the capsules are striate rather than smooth. Because of its habit and the absence of a central strand, K. G. Limpricht ([1885–]1890–1903, vol. 1) placed it, together with G. hartmanii and G. atrata, in Dryptodon, a genus intermediate between Grimmia and Racomitrium. There are many other Grimmia species, however, without a central strand, and G. hartmanii and G. atrata have already been removed from Dryptodon, so there is no reason to maintain that monotypic genus. Grimmia ramondii may be confused with G. hartmanii and G. elatior. However, the lack of awns, the Racomitrioideae-like areolation, and the distinct costal wings distinguish it easily from those species.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Grimmia elatior is fairly common in the Canadian Rockies and in the western United States. It is predominantly bound to the Rocky Mountain area in Colorado, Wyoming, and Montana. In eastern North America it is known only from a site in New Jersey. It can be recognized easily by its robust habit, usually growing in dark green, extended patches on various types of acidic rock, like gneiss, granite, and sandstone. While it is often described as having papillae, most North American specimens do not have them. E. M. Mair (2002) reported that papillae were strongly expressed in harsh conditions but many specimens from the alpine in both the Yukon and Colorado lack papillae. The widespread but uncommon western species G. leibergii is commonly mistaken for G. elatior. However, the former has both leaf margins recurved, its lamina is 1-stratose with only 2-stratose margins, and its basal juxtacostal cells are elongate to linear; in G. elatior there is only one recurved leaf margin, its lamina is 2-stratose with multistratose bands and margins, and its basal juxtacostal cells are only short- to long-rectangular. The length of the awn in G. elatior is quite variable; plants with nearly muticous leaves and plants with very long awns may be found growing close together. There is also some resemblance to G. pilifera, widespread in Asia and eastern North America. The latter, however, has immersed capsules, both margins are recurved, and its lamina does not have multistratose bands.

(Discussion copyrighted by Flora of North America; reprinted with permission.)