Grimmia longirostris |
Grimmia elatior |
|
---|---|---|
grimmia dry rock moss |
grimmia dry rock moss, large grimmia |
|
Habit | Plants in compact cushions, yellow-green to dark olivaceous. | Plants in robust, dark green to blackish green, loose, hoary, readily disintegrating tufts. |
Stems | 1–3 cm, central strand strong. |
1–5 cm, central strand absent. |
Gemmae | absent. |
|
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 to slightly twisted when dry, erectopatent when moist, lanceolate to ovate-lanceolate, tapering to acute apex, 2–3.0 × 0.5–0.7 mm, keeled, margin broadly recurved on one side, awns short to long and weakly denticulate, costa weak at base, channeled distally, projecting on abaxial side; basal juxtacostal laminal cells short- to long-rectangular, sinuose-nodulose, thick-walled; basal marginal laminal cells quadrate to short-rectangular, thin- to thick-walled; medial laminal cells quadrate to short-rectangular, sinuose, thick-walled; distal laminal cells 2-stratose with thick, prominent multistratose bands, margins multistratose and thick, areolation very opaque with rounded thick-walled cells, occasionally papillose. |
Seta | straight, (1–)2–4 mm. |
arcuate, 2–3 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, emergent to exserted, brown, obloid, striate, exothecial cells thin-walled, annulus present, operculum rostrate, peristome teeth purple, deeply split, papillose. |
Calyptra | mitrate. |
|
Grimmia longirostris |
Grimmia elatior |
|
Habitat | Exposed, dry, acidic granite and quartzite | Exposed, dry acidic rock and occasionally basic limestone |
Elevation | low to high eleavations (100-3100 m) [low to high eleavations (300-10200 ft)] | moderate to high elevations (500-4500 m) [moderate to high elevations (1600-14800 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
|
CO; MT; NJ; OR; SD; WY; AB; BC; YT; Greenland; Eurasia; Africa |
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.) |
Grimmia elatior is fairly common in the Canadian Rockies and in the western United States. It is predominantly bound to the Rocky Mountain area in Colorado, Wyoming, and Montana. In eastern North America it is known only from a site in New Jersey. It can be recognized easily by its robust habit, usually growing in dark green, extended patches on various types of acidic rock, like gneiss, granite, and sandstone. While it is often described as having papillae, most North American specimens do not have them. E. M. Mair (2002) reported that papillae were strongly expressed in harsh conditions but many specimens from the alpine in both the Yukon and Colorado lack papillae. The widespread but uncommon western species G. leibergii is commonly mistaken for G. elatior. However, the former has both leaf margins recurved, its lamina is 1-stratose with only 2-stratose margins, and its basal juxtacostal cells are elongate to linear; in G. elatior there is only one recurved leaf margin, its lamina is 2-stratose with multistratose bands and margins, and its basal juxtacostal cells are only short- to long-rectangular. The length of the awn in G. elatior is quite variable; plants with nearly muticous leaves and plants with very long awns may be found growing close together. There is also some resemblance to G. pilifera, widespread in Asia and eastern North America. The latter, however, has immersed capsules, both margins are recurved, and its lamina does not have multistratose bands. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 27, p. 239. | FNA vol. 27, p. 250. |
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 | G. cognata, G. grandis, G. papillosa |
Name authority | Hooker: Musci Exot. 1: plate 62. (1818) | Bruch ex Balsamo-Crivelli & De Notaris: Mem. Reale Accad. Sci. Torino 40: 340. (1838) |
Web links |