Flora of North America species comparison

Of conservation concern.

Previous to its discovery in Iceland, as Grimmia grisea (H. C. Greven 1998), G. reflexidens was known from only the Southern Hemisphere. It had previously been collected east of East Bay, Newfoundland, now the only known locality in North America, but was not recognized as G. reflexidens. The latter is similar to G. asperitricha Dixon & Sainsbury of New Zealand, and the two species have been confused by G. O. K. Sainsbury (1945) as well as by R. Ochyra (1993). J. Muñoz (1998b) synonymized G. reflexidens with G. sessitana. However, the former is readily separated from the latter by: (1) enlarged perichaetial leaves, (2) decurrent awns, (3) non-bulging laminal cells, and (4) dioicous sexual condition. Capsules are unknown from Northern Hemisphere material, but G. reflexidens lacks stomata while they are present for G. sessitana. Although G. reflexidens and G. teretinervis both have decurrent awns they are easily separated by a number of characters: G. reflexidens grows in compact cushions, has long awns, and a semicircular costa; G. teretinervis grows in loose clumps, is hyaline-tipped to short-awned, and has a unique costa that is distally almost completely circular in transverse section.

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

In North America, Grimmia crinitoleucophaea is known from only scattered localities in the American west and in three extremely disjunct sites in Canada: in southern British Columbia, near the Keele River of the Northwest Territories, and along the Dempster Highway in the Yukon. It is found on a broad range of both basic and acidic rock types. Its subgeneric placement is problematic. Gametophytically the species is inseparable from G. tergestina, of subg. Litoneuron. Indeed, based on areolation and leaf shape, L. Loeske (1913–1914, part 1) placed it as a subspecies of the latter. This close similarity may account for reports by J. Muñoz and F. Pando (2000) and D. H. Norris and J. R. Shevock (2004) of G. tergestina from North America. We have seen all cited specimens in these papers and they all represent G. crinitoleucophaea or G. ovalis. Therefore, we reject G. tergestina being in North America. Sporophytic characters of G. crinitoleucophaea (a short, arcuate to sigmoid seta that is eccentrically attached to the capsule, an immersed ventricose capsule with a small, mitrate calyptra, and 3–4 large stomata) clearly indicate membership in subg. Grimmia. Further, G. crinitoleucophaea and G. tergestina have never been collected together, suggesting that the two are also ecologically distinct. Despite its dioicous sexuality, G. crinitoleucophaea is usually fertile; its rudimentary peristome and large annulus are thus readily evident. Its 2-stratose laminal stratification separates it from specimens of G. plagiopodia that may have broken peristome teeth.

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