Grimmia longirostris |
Grimmia lesherae |
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grimmia dry rock moss |
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Habit | Plants in compact cushions, yellow-green to dark olivaceous. | Plants in loose tufts, green. |
Stems | 1–3 cm, central strand strong. |
0.5–1.5 cm, dichotomously branched, central strand absent. |
Gemmae | absent. |
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Leaves | ovate-lanceolate, 1.5–3 × 0.6–0.7 mm, keeled, one margin recurved proximally, not sheathing, awn 0.5–1.5 mm, costal transverse section prominent, reniform; basal juxtacostal laminal cells long-rectangular to linear, sinuose, thick-walled; basal marginal laminal cells short-rectangular, straight, with thick transverse and thin lateral walls, hyaline; medial laminal cells short-rectangular, sinuose, thick-walled; distal laminal cells 2-stratose, not bulging, marginal cells 2-stratose, not bulging. |
loosely appressed and straight when dry, erectopatent when moist, broadly oblong-lanceolate, tapering to acute apex, 1.5–2 × 0.4–0.6 mm, larger towards stem tips, sharply keeled, margins recurved on both sides, awns absent, occasionally short hyaline points at leaf tips present, costa weak proximally, broad distally, projecting on abaxial side; basal juxtacostal laminal cells rectangular to linear, straight, thin-walled; basal marginal laminal cells rectangular, thin-walled; medial laminal cells short-rectangular with nodulose to sinuose walls, weakly papillose; distal laminal cells 1-stratose, margins 2-stratose. |
Seta | straight, (1–)2–4 mm. |
straight, 2 mm. |
Sexual condition | cladautoicous, perichaetial leaves not enlarged. |
dioicous. |
Capsule | usually present, (emergent to) exserted, yellow, oblong-ovoid to cylindric, exothecial cells short- to long-rectangular, thin-walled, stomata present in 2–3 rows, annulus of 2 rows of rectangular, thick-walled cells, operculum long-rostrate, peristome present, fully-developed, split and perforate in distal half. |
occasionally present, exserted, yellowish brown, oblate, smooth, exothecial cells thin-walled, annulus present, operculum rostrate, peristome teeth orange, deeply split and perforated, papillose. |
Calyptra | cucullate. |
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Grimmia longirostris |
Grimmia lesherae |
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Habitat | Exposed, dry, acidic granite and quartzite | Damp acidic rock |
Elevation | low to high eleavations (100-3100 m) [low to high eleavations (300-10200 ft)] | high elevations (2000-3000 m) [high elevations (6600-9800 ft)] |
Distribution |
AK; AZ; CA; CO; ID; ME; MN; MT; NC; NH; NM; NV; OK; OR; SD; TX; UT; VT; WA; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; QC; SK; YT; Mexico; South America; Africa; Pacific Islands; Greenland; Eurasia; Central America (Costa Rica, Guatemala, Honduras); Australia
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CA; WA |
Discussion | Grimmia longirostris is one of the most common species of the genus. It is most common in the eastern ranges of the Rocky Mountains, ranging from western Texas through the Canadian Rockies, and throughout much of Alaska. It is widely distributed in the Canadian sub-Arctic and Arctic, and is known from Greenland. With the exception of disjunct sites in Oklahoma and North Carolina, it is absent in the American Great Plains and Southeast. These latter areas are largely composed of calcareous rocks, a substrate avoided by G. longirostris. It is rare in coastal areas, becoming more common inland. As Grimmia affinis, G. longirostris has commonly been placed as a subspecies of G. ovalis. Despite G. Sayre’s (1951) resolution of the differences between these taxa, a large proportion of specimens in major herbaria in North America that are named G. ovalis are actually G. longirostris. However, G. ovalis is dioicous and has leaves with plane margins that are broadly concave distally, usually with a distinct ovate base and well-defined shoulders. In contrast, G. longirostris is autoicous, and has leaves with one recurved margin, that are narrowly keeled distally, with a poorly defined basal region, often without a distinct shoulder. These characters clearly separate these two taxa at the specific level. Hastings puts G. longirostris into a group that also includes G. arizonae and G. pilifera. Grimmia longirostris is separated from those two species by non-sheathing leaf bases, usually long-exserted capsules, and cladautiocous sexuality. Grimmia longirostris is further separated from G. pilifera by having a stem with a distinct central strand and a thin epidermis, a costal transverse section that is typically reniform, and leaves that are recurved on only one margin. Rare specimens of G. longirostris with immersed capsules in the American Southwest may be almost indistinguishable from G. arizonae. In extremely xeric environments, specimens become friable and break into individual strands, making determination of the cladautiocous sexuality impossible. In these circumstances identification will always be uncertain. However, the leaves of G. longirostris are not sheathing; they are only loosely attached to the stem and usually can be peeled off intact. In contrast, the leaves of G. arizonae are sheathing and strongly attached to the stem; they often break at the base when trying to remove them. The costal transverse sections of G. longirostris are characteristically reniform (J. Muñoz 1998) while those of G. arizonae are usually semicircular. However, gradations from semicircular to reniform are not uncommon. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Grimmia lesherae is apparently endemic to the high mountains along the Pacific Coast of western North America. At present, it is known only from a few damp high elevation sites in Washington and northern California, but suitable habitats exist all along the high coastal mountains and so it may also be expected in Oregon. It is a distinctive species that is unlikely to be confused with others. There are some similarities to G. incurva, but that species has short hair-points, the leaves are linear, the medial cells have nodulose walls, and the seta is arcuate. The combination of keeled leaves with recurved margins, and straight seta is unique in the subgenus. Grimmia lesherae appears to be intermediate between subg. Guembelia and subg. Rhabdogrimmia, calling into question the division of the genus into four subgenera. A peculiar distinguishing character is the left-handed twist of dried-up setae, unique in the genus. K. G. Limpricht ([1885–]1890–1893, vol. 1) incorrectly reported the left-hand twisted, dried up setae as common in Grimmia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 27, p. 239. | FNA vol. 27, p. 248. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | G. affinis, G. arctophila subsp. labradorica, G. catalinensis, G. catalinensis var. mutica, G. elata, G. ortholoma, G. ovalis var. affinis, G. ovata var. affinis, G. ovateoformis | |
Name authority | Hooker: Musci Exot. 1: plate 62. (1818) | Greven: Grimmias, 130, figs. 43a–f. (2003) |
Web links |