Grimmia trichophylla |
Grimmia moxleyi |
|
---|---|---|
grimmia dry rock moss, hair-point grimmia |
moxley's dry rock moss |
|
Habit | Plants in dense to loose patches, yellowish green to dark green. | Plants in frequently extended mats, blackish green. |
Stems | 2–4 cm, central strand present. |
1–1.5 mm high, small central strand present. |
Gemmae | clusters occasionally present in distal leaf axils. |
absent. |
Leaves | loosely appressed, slightly twisted when dry, erecto-patent when moist, lanceolate to oblong-lanceolate, tapering to acute apex, 2–3.5 × 0.3–0.4 mm, usually sharply keeled, margins recurved on one or both sides, plane to erect distally, awns variable, short to long, smooth to denticulate, not conspicuously flattened at base, costa firm, projecting on abaxial side; basal juxtacostal laminal cells long-rectangular (rarely short-rectangular), ± nodulose, thick-walled; basal marginal laminal cells short- to long-rectangular, with thickened transverse walls; medial laminal cells quadrate to short-rectangular, slightly sinuose, thick-walled; distal laminal cells 1-stratose, occasionally with 2-stratose ridges. |
erect with slightly incurved tips when dry, erect-spreading when moist, oblong, broadly rounded and muticous at apex, 1.5–2 × 0.4–0.6 mm, keeled, margins plane to recurved, awns absent, only present in perichaetial leaves, costa weak proximally, projecting at abaxial side, perichaetial leaves longer and with awns; basal juxacostal laminal cells short- to long-rectangular, straight, thin-walled; basal marginal laminal cells short- to long-rectangular, thin-walled; medial laminal cells rounded-quadrate, ± sinuose, thin- or thick-walled; distal laminal cells 2-stratose. |
Seta | arcuate, 2–4 mm. |
flexuose to arcuate, 1–1.5 mm. |
Sexual condition | dioicous. |
autoicous. |
Capsule | occasionally present, exserted, oblong-ovoid, yellowish green to stramineous, striate when dry, exothecial cells thin-walled, annulus present, operculum rostrate, peristome teeth yellowish, papillose, deeply split and perforated. |
usually present, exserted, chestnut brown, oblong-ovoid, wrinkled-plicate when dry, exothecial cells thin- to thick-walled, annulus present, operculum conical, peristome teeth yellowish, split and perforated, papillose. |
Calyptra | mitrate. |
cucullate. |
Grimmia trichophylla |
Grimmia moxleyi |
|
Habitat | Dry, acidic rock | Dry acidic rock |
Elevation | moderate to high elevations (200-2000 m) (moderate to high elevations (700-6600 ft)) | moderate elevations (500-1500 m) (moderate elevations (1600-4900 ft)) |
Distribution |
AZ; CA; CO; ID; ME; MO; MT; NV; OK; OR; SD; UT; VT; WA; WY; HI; BC; Mexico; Eurasia; Australia
|
AZ; CA; NV; Mexico |
Discussion | 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 moxleyi is endemic to the southwestern United States and northwestern Mexico. A thermophilous species from acidic rock, it is autoicous and usually richly provided with capsules. The species is characterized by growing in flat, easily disintegrating patches with short, keeled, muticous stem leaves that contrast with its much larger awned perichaetial leaves. J. Muñoz (2000) synonymized G. moxleyi with G. orbicularis. Although there are some similarities, G. orbicularis is much larger, grows in dense cushions on basic rock, has setae 2–3 mm, shiny, spherical capsules, and a mammilate operculum. Only the most proximal stem leaves of G. orbicularis are muticous and the basal juxtacostal cells have thick, nodulose walls. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 27, p. 257. | FNA vol. 27, p. 254. |
Parent taxa | Grimmiaceae > subfam. Grimmioideae > Grimmia > subg. Rhabdogrimmia | Grimmiaceae > subfam. Grimmioideae > Grimmia > subg. Rhabdogrimmia |
Sibling taxa | ||
Name authority | Greville: Fl. Edin., 235. (1824) | R. S. Williams: in J. M. Holzinger, Musci Acroc. Bor.-Amer., 600. (1926) |
Web links |