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grimmia dry rock moss

grimmia dry rock moss, hoary grimmia

Habit Plants in compact cushions, yellow-green to dark olivaceous. Plants in hoary, dense tufts, dark green to dark brown.
Stems

1–3 cm, central strand strong.

0.5–2 cm.

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.

oblong-ovate to oblong-lanceolate, 1.5–3 × 0.4–0.6 mm, both margins plane, intermarginal bands absent, awn 0.3–2 mm, decurrent, broadly attached, acute, costa broad proximally;

basal juxtacostal laminal cells elongate, straight, thick lateral walls, green;

basal marginal laminal cells oblate to quadrate, straight, thick transverse and thin lateral walls, green, not hyaline;

medial laminal cells rounded-quadrate, straight, thick-walled;

distal laminal cells 2-stratose, quadrate, thick-walled.

Seta

straight, (1–)2–4 mm.

straight, 1.5–3 mm.

Sexual condition

cladautoicous, perichaetial leaves not enlarged.

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, brown, oblong-ovoid to cylindric, exothecial cells quadrate, thick-walled, stomata present, annulus of 2–3 rows of rectangular, thick-walled cells, operculum short rostrate, peristome irregularly perforate distally, irregularly split.

Calyptra

mitrate.

Perichaetial

leaves not enlarged.

Grimmia longirostris

Grimmia laevigata

Habitat Exposed, dry, acidic granite and quartzite Humid to dry, exposed, acidic, sandstone and granite and basalt, open plains to montane, rarely alpine
Elevation low to high eleavations (100-3100 m) [low to high eleavations (300-10200 ft)] moderate to high elevations (200-2800 m) [moderate to high elevations (700-9200 ft)]
Distribution
from FNA
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
[WildflowerSearch map]
from FNA
AL; AR; AZ; CA; CO; DC; FL; GA; IA; ID; IL; IN; KS; KY; MA; MD; MN; MO; MT; NC; NE; NJ; NM; NV; NY; OK; OR; PA; SC; SD; TN; TX; UT; VA; VT; WA; WY; BC; Mexico; South America; Eurasia; Africa; Indian Ocean Islands; Australia
[WildflowerSearch map]
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 laevigata is widespread and relatively common on the southern Great Plains, into the Ozarks, and along the Appalachians from northeastern Alabama to New England. There is also an extensive outlier in southern Minnesota and adjacent states. In western North America, it is abundant in California and the Pacific Northwest region into south central British Columbia. Although it occurs in the Rocky Mountain region it is not common there, being found mostly in lower elevation sites and along the east slopes. With the exception of a few disjunct sites in southern Georgia and Florida, it is unknown from the coastal plains of the American southeast. This is probably related to the extensive cover of calcareous Cretaceous and more recent bedrock. The northern limit of G. laevigata suggests a distribution influenced by the winter position of the Arctic airmass. Although known from high elevations, it is most often found below treeline on granite and acidic sandstones. It is an early successional invader of granitic rocks in the southeastern piedmont (H. J. Oosting and L. E. Anderson 1937, 1939; C. Keever et al. 1951). Classic specimens of G. laevigata are recognized by their broad leaves with almost no shoulder separating the proximal and distal lamina, and by their robust, broadly attached and long-decurrent awns. However, G. laevigata is quite variable with respect to leaf shape and awn attachment, with some specimens having bases approaching ovate and then often with rather narrowly attached awns. These specimens may be assigned to G. laevigata by the wide costa and oblate to quadrate basal marginal cells. Sterile specimens may be separated from G. crinitoleucophaea by the wide costa and thick-walled basal cells.

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

Source FNA vol. 27, p. 239. FNA vol. 27, p. 247.
Parent taxa Grimmiaceae > subfam. Grimmioideae > Grimmia > subg. Guembelia Grimmiaceae > subfam. Grimmioideae > Grimmia > subg. Litoneuron
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. 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
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. 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. 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 Campylopus laevigatus, G. glauca, G. leucophaea, G. sarcocalyx
Name authority Hooker: Musci Exot. 1: plate 62. (1818) (Bridel) Bridel: Bryol. Univ. 1: 183. (1826)
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