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.)

Of conservation concern.

Grimmia mariniana is known only from the coastal mountains of central California. If fertile, the immersed capsules with rudimentary peristome teeth will separate it from both G. montana and G. alpestris, which, while also being dioicous and without stomata, have long-exserted capsules with fully-developed peristome teeth. Grimmia nevadensis is similar but lacks peristome teeth, has uniformly rectangular, thin-walled basal laminal cells, and does not have hyaline margins. The faint ribs on the capsules of G. mariniana may not be evident when the capsules are not turgid. Sterile specimens can be separated from G. alpestris by the lack of bulging cells, and the narrow leaves. Distinguishing sterile specimens of G. mariniana from G. montana is more problematic, as both have narrowly ovate-lanceolate leaves, with similar areolation. However, the basal marginal laminal cells of G. mariniana are hyaline while those of G. montana are not. Grimmia mariniana is easily separated from G. arizonae and G. pilifera, two other members of the subgenus, along with G. nevadensis, that have immersed capsules. Sporophytically, both G. arizonae and G. pilifera have abundant stomata, well-developed peristome teeth, and rectangular, thick-walled, multi-layered annuli. Gametophytically, the incurved leaf margins of G. mariniana contrast sharply with the recurved leaf margins of G. arizonae and G. pilifera. Sayre noted the similarity of G. mariniana to G. anodon. The straight, centrally attached seta and symmetric capsule usually with rudimentary peristome teeth will serve to separate specimens of G. mariniana from G. anodon. Gametophytically, the long, narrow leaves, with incurved margins and 2-stratose distal laminal cells separates G. mariniana from G. anodon.

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