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grimmia dry rock moss

Habit Plants in compact hairy cushions, grayish green. Plants in robust, loose tufts, dark olivaceous to black.
Stems

1–2 cm, central strand absent.

1–4 cm, central strand absent.

Leaves

ovate to oblong-lanceolate, 0.1–1.15 × 0.3–0.5 mm, keeled, not plicate, margins plane, awns 1–2 mm, very long, smooth to slightly denticulate, flattened basally, long-decurrent, costal transverse section prominent, semi-circular;

basal juxtacostal laminal cells rectangular, sometimes nodulose, thin- to thick-walled;

basal marginal laminal cells rectangular with thickened transverse walls, pellucid in 2–4 rows;

medial laminal cells rounded-quadrate, slightly sinuose, thick-walled;

distal laminal cells yellowish green, 1-stratose with 2-stratose ridges, not bulging, marginal cells 2-stratose, not bulging.

narrowly lanceolate from an ovate base, 2–4.5 × 0.4–0.8 mm, keeled, both margins recurved proximally, often narrowly, sheathing, awn 0.2–0.6(–1.5) mm, costal transverse section prominent, usually semicircular;

basal juxtacostal laminal cells short-rectangular to linear, sinuose, thin transverse and thick lateral walls;

basal marginal laminal cells quadrate to short-rectangular, straight to sinuose, thick transverse and thin lateral walls, hyaline;

medial laminal cells quadrate to short-rectangular, sinuose, thick-walled;

distal laminal cells 2-stratose, not bulging, marginal cells (2–)3(–4)-stratose, not bulging.

Seta

straight, 0.5–1 mm.

Sexual condition

dioicous, perichaetial leaves enlarged.

dioicous, perichaetial leaves not enlarged.

Capsule

absent in northern hemisphere material, emergent to shortly exserted, yellowish brown, oblate, exothecial cells irregularly short-rectangular, thin-walled, stomata absent, annulus of 1 row of quadrate, thick-walled cells, operculum mammillate to rostrate, peristome present, nearly fully-developed, split and perforated only in apex, papillose.]

occasionally present, immersed, yellow, oblong-ovoid, exothecial cells quadrate to short-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, perforate in middle, split in distal half.

[seta straight, 1.5–2 mm.

Grimmia reflexidens

Grimmia pilifera

Habitat Dry acidic rock Exposed to tree shaded, dry limestone, sandstone and granite
Elevation low [to moderate] elevations (50[-300] m) (low [to moderate] elevations (200[-1000] ft)) low to high elevations (60-2300 m) (low to high elevations (200-7500 ft))
Distribution
from FNA
NF; South America (Argentina, Chile); Atlantic Islands (Iceland); Pacific Islands (New Zealand); Australia
from FNA
AL; AR; AZ; CO; CT; DE; GA; IL; IN; KY; MA; MD; ME; MN; MO; MT; NC; NJ; NM; NY; PA; RI; SD; TN; VA; VT; WV; NS; ON; Mexico; Asia
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Discussion

Of conservation concern.

Previous to its discovery in Iceland, as Grimmia grisea (H. C. Greven 1998), G. reflexidens was known from only the Southern Hemisphere. It had previously been collected east of East Bay, Newfoundland, now the only known locality in North America, but was not recognized as G. reflexidens. The latter is similar to G. asperitricha Dixon & Sainsbury of New Zealand, and the two species have been confused by G. O. K. Sainsbury (1945) as well as by R. Ochyra (1993). J. Muñoz (1998b) synonymized G. reflexidens with G. sessitana. However, the former is readily separated from the latter by: (1) enlarged perichaetial leaves, (2) decurrent awns, (3) non-bulging laminal cells, and (4) dioicous sexual condition. Capsules are unknown from Northern Hemisphere material, but G. reflexidens lacks stomata while they are present for G. sessitana. Although G. reflexidens and G. teretinervis both have decurrent awns they are easily separated by a number of characters: G. reflexidens grows in compact cushions, has long awns, and a semicircular costa; G. teretinervis grows in loose clumps, is hyaline-tipped to short-awned, and has a unique costa that is distally almost completely circular in transverse section.

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

Grimmia pilifera is most commonly found in the Appalachian Mountains from Nova Scotia to New York and south to northern Georgia and Alabama. It extends into the Midwest on the Ozark Plateau northward to southern Illinois and Indiana. It is rare in western North America, being found in mountainous areas in southeastern Arizona to the Rocky Mountain Front Ranges of New Mexico and Colorado, with disjunct sites in Montana, western South Dakota, and Minnesota. It occupies a broader range of habitats than does either G. longirostris or G. arizonae in that it is common on limestone and sandstone, as well as granites, in shaded as well as exposed sites, and at much lower elevations throughout much of its range, while still reaching the alpine in Colorado. Grimmia pilifera is most closely related to a group that includes G. longirostris and G. arizonae. Its lack of a central strand, and its leaves with a small, well-defined ovate base recurved on both margins, which are also distinctly thick, will separate it from G. arizonae.

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

Source FNA vol. 27, p. 238. FNA vol. 27, p. 241.
Parent taxa Grimmiaceae > subfam. Grimmioideae > Grimmia > subg. Guembelia Grimmiaceae > subfam. Grimmioideae > Grimmia > subg. Guembelia
Sibling taxa
G. alpestris, G. americana, G. anodon, G. anomala, G. arizonae, G. atrata, G. attenuata, G. brittoniae, G. caespiticia, G. crinitoleucophaea, G. donniana, G. elatior, G. elongata, G. funalis, G. hamulosa, G. hartmanii, G. incurva, G. laevigata, G. leibergii, G. lesherae, G. lisae, G. longirostris, G. mariniana, G. mollis, G. montana, G. moxleyi, G. muehlenbeckii, G. nevadensis, G. olneyi, G. orbicularis, G. ovalis, G. pilifera, G. plagiopodia, G. pulvinata, G. ramondii, G. serrana, G. sessitana, G. shastae, G. teretinervis, G. torquata, G. trichophylla, G. unicolor
G. alpestris, G. americana, G. anodon, G. anomala, G. arizonae, G. atrata, G. attenuata, G. brittoniae, G. caespiticia, G. crinitoleucophaea, G. donniana, G. elatior, G. elongata, G. funalis, G. hamulosa, G. hartmanii, G. incurva, G. laevigata, G. leibergii, G. lesherae, G. lisae, G. longirostris, G. mariniana, G. mollis, G. montana, G. moxleyi, G. muehlenbeckii, G. nevadensis, G. olneyi, G. orbicularis, G. ovalis, G. plagiopodia, G. pulvinata, G. ramondii, G. reflexidens, G. serrana, G. sessitana, G. shastae, G. teretinervis, G. torquata, G. trichophylla, G. unicolor
Synonyms G. grisea G. pensylvanica
Name authority Müller Hal.: Syn. Musc. Frond. 1: 795. (1849) P. Beauvois: Prodr. Aethéogam., 58. (1805)
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