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.

Few collections of Grimmia hamulosa exist, its habitat is not well defined, and it is a somewhat confusing species. The original description is incomplete and partly incorrect, e.g. it lacks discussion and comparison with related taxa, and the seta is straight, not bent, as stated in the protologue. The species is characterized by: (1) a glossy habit with long tapering, homomallous, muticous leaves with plane margins; (2) a broad, weakly outlined costa that fills the distal part of the 2-stratose lamina; and (3) a glossy exserted capsule that lacks an annulus. Despite its unique leaf characters and lack of an annulus, Hastings has put it in subg. Litoneuron based on its thick, concave leaves with plane margins, costa not projecting prominently from the lamina, and exserted capsule on a straight seta. In 1999, Greven found G. hamulosa richly fruiting in Yosemite National Park. Although isotypes studied by Greven have muticous leaves, in some of the plants from Yosemite the leaves have inconspicuous short awns. However, these plants do not deviate in other aspects from the type specimen. Small specimens of this species resemble G. fragilis Schimper, a form of G. montana described from southern Europe. These plants are characterized by long, glossy leaves usually with broken tips. In G. hamulosa, the leaf tips are also frequently broken; however, in G. montana the costa is clearly defined, and the distal leaf margins are incurved.

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