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Habit Plants in compact hairy cushions, grayish green. Plants in robust, loose, arched-ascending, readily disintegrating patches, brownish green distally, blackish proximally.
Stems

1–2 cm, central strand absent.

5–10 cm, central strand absent.

Gemmae

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.

loosely appressed when dry, patent when moist, broadly ovate-lanceolate, tapering to an acute, slightly toothed apex, 2–3 × 0.4–0.6 mm, keeled, margins recurved on both sides, awns absent, costa stout, with two abaxial lamellae (or wings) forming parallel ridges along its length;

basal juxtacostal laminal cells yellow, linear, sinuose, thick-walled;

basal marginal laminal cells quadrate to short-rectangular, slightly thick-walled;

medial laminal cells quadrate to rectangular, sinuous, thick-walled;

distal laminal cells 1-stratose, margins 2-stratose.

Seta

cygneous to arcuate at maturity, flexuose when old, 3–5 mm.

Sexual condition

dioicous, perichaetial leaves enlarged.

dioicous.

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, exserted, obloid, yellowish green to yellowish brown, plicate when empty, exothecial cells thin-walled, annulus present, operculum rostrate, peristome teeth purple, divided nearly to base into two partly adhering segments, papillose.

Calyptra

mitrate.

[seta straight, 1.5–2 mm.

Grimmia reflexidens

Grimmia ramondii

Habitat Dry acidic rock Dry to damp acidic rock
Elevation low [to moderate] elevations (50[-300] m) (low [to moderate] elevations (200[-1000] ft)) low to high elevations (0-2000 m) (low to high elevations (0-6600 ft))
Distribution
from FNA
NF; South America (Argentina, Chile); Atlantic Islands (Iceland); Pacific Islands (New Zealand); Australia
from FNA
AK; CA; ID; MI; MT; OR; WA; AB; BC; NF; NT; Greenland; Europe; Asia (China, Japan); n 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 ramondii occurs near sea level in arctic areas and along the West Coast. In the latter region, however, it is more common in mid-elevation montane sites and may also be found above the tree line. It differs from most Grimmia species by its lack of awns, winged costa, and tall, loose growth form. At first sight, G. ramondii has the habit of a Racomitrium. However, the sporophyte has an arcuate rather than straight seta, and the capsules are striate rather than smooth. Because of its habit and the absence of a central strand, K. G. Limpricht ([1885–]1890–1903, vol. 1) placed it, together with G. hartmanii and G. atrata, in Dryptodon, a genus intermediate between Grimmia and Racomitrium. There are many other Grimmia species, however, without a central strand, and G. hartmanii and G. atrata have already been removed from Dryptodon, so there is no reason to maintain that monotypic genus. Grimmia ramondii may be confused with G. hartmanii and G. elatior. However, the lack of awns, the Racomitrioideae-like areolation, and the distinct costal wings distinguish it easily from those species.

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

Source FNA vol. 27, p. 238. FNA vol. 27, p. 256.
Parent taxa Grimmiaceae > subfam. Grimmioideae > Grimmia > subg. Guembelia Grimmiaceae > subfam. Grimmioideae > Grimmia > subg. Rhabdogrimmia
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. pilifera, G. plagiopodia, G. pulvinata, G. reflexidens, G. serrana, G. sessitana, G. shastae, G. teretinervis, G. torquata, G. trichophylla, G. unicolor
Synonyms G. grisea Pterigynandrum ramondii, Dryptodon patens, G. curvata, Racomitrium patens
Name authority Müller Hal.: Syn. Musc. Frond. 1: 795. (1849) (Lamarck & De Candolle) Margadant: Lindbergia 1: 128. (1972)
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