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grimmia dry rock moss

Habit Plants in compact hairy cushions, grayish green. Plants in dense patches, reddish brown to blackish green.
Stems

1–2 cm, central strand absent.

1–4 cm, central strand present.

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.

lanceolate, keeled, not plicate, one margin commonly narrowly recurved, awns 0.1–0.5 mm, lower leaves muticous, costal transverse section weak at base, semicircular distally;

basal juxtacostal laminal cells elongate, straight, somewhat thick-walled;

basal marginal laminal cells rectangular with straight walls, often hyaline;

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

distal laminal cells 1-stratose, not bulging, marginal cells 2-stratose, not bulging.

Seta

straight to slightly arcuate, 1.5–2.5 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, emergent to shortly exserted, yellow-brown, ovoid, exothecial cells variable, quadrate to rectangular, thin-walled, stomata present, annulus of 1–3 rows, operculum conical to rostrate, peristome present, fully-developed, papillose.

[seta straight, 1.5–2 mm.

Grimmia reflexidens

Grimmia elongata

Habitat Dry acidic rock Damp acidic volcanic rock and sandstone, high elevation forests to tundra
Elevation low [to moderate] elevations (50[-300] m) (low [to moderate] elevations (200[-1000] ft)) moderate to high elevations (400-2400 m) (moderate to high elevations (1300-7900 ft))
Distribution
from FNA
NF; South America (Argentina, Chile); Atlantic Islands (Iceland); Pacific Islands (New Zealand); Australia
from FNA
CO; AB; NT; NU; QC; Mexico; Central America; South America; Greenland; Eurasia; Africa
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 elongata is a widely distributed species mainly occurring above 2000 m, and with a preference for acidic sandstones and volcanic, damp, north-facing outcrops and ledges. It seems to be uncommon in North America, having been collected only occasionally and from widely separated localities. However, the wide distribution of G. elongata across the Northern Hemisphere suggests that it may be more common on this continent than collection records indicate. Cao T. and D. H. Vitt (1986b) noted that in North America, specimens of G. elongata would be confused most likely with G. donniana, as they considered the two species to be closely related. However, these species are distinctly different in a number of clear characters: G. elongata is reddish brown, muticous or short-awned, has one leaf margin recurved and is dioicous. In contrast, G. donniana is green to black, long-awned, has plane leaf margins and is autoicous. These characters lead us to believe that these species are not closely related; H. C. Greven (2003) believed that G. elongata is most closely related to the Himalayan endemic G. redunca Mitten.

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

Source FNA vol. 27, p. 238. FNA vol. 27, p. 236.
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. 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. reflexidens, G. serrana, G. sessitana, G. shastae, G. teretinervis, G. torquata, G. trichophylla, G. unicolor
Synonyms G. grisea Dryptodon elongatus
Name authority Müller Hal.: Syn. Musc. Frond. 1: 795. (1849) Kaulfuss: in J. Sturm et al., Deutschl. Fl. 2(15): plate 14. (1816)
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