Flora of North America species comparison

In North America, Grimmia trichophylla is principally a lowland species, occurring in the mountains up to about 1000 m., rarely higher. In the Southern Hemisphere, it may be found up to 4000 m. In New Zealand, the species is common, and in contrast to G. trichophylla in North America, frequently bears capsules. The New Zealand plants are usually smaller than American specimens, and the leaves are frequently contorted. The nearly cosmopolitan G. trichophylla has many phenotypes, and numerous subspecies and varieties have been described. In damp and shaded habitats, the awns may be short, just as in dry unfavorable habitats at high altitudes, where stunted specimens may occur with small, short leaves and reduced awns, or even with muticous leaves. Grimmia trichophylla has frequently been confused with related species such as 36. G. muehlenbeckii and 34. G. lisae (see discussions thereunder for identification details). Robust forms of G. trichophylla have been mistaken for G. austrofunalis (H. C. Greven 1997, 2003), which does not occur in North America. Although some of those plants have leaves of equal length along the stem, characteristic of G. austrofunalis, they also have both leaf margins recurved, and the medial and outer basal laminal cells are longer and more robust than in that 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.)