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grimmia dry rock moss

grimmia dry rock moss

Habit Plants in compact cushions, yellow-green to dark olivaceous. Plants growing in dense, usually hemispherical cushions, breaking up readily, falling apart into clusters and string-like (spirally twisted leaves) single shoots, grayish green.
Stems

1–3 cm, central strand strong.

2–5 cm, central strand present.

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.

usually spirally arranged when dry, patent when moist, lanceolate, 0.5–1.5 × 0.2–0.5 mm, appressed, of ± uniform length throughout stem, keeled, margins plane or recurved on one side, in female plants awns long and denticulate, in male plants very short to absent, costa weak proximally, projecting on abaxial side;

basal juxtacostal laminal cells elongate, ± sinuose, thick-walled;

basal marginal proximal laminal cells short-rectangular, hyaline;

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

distal laminal cells 2-stratose.

Seta

straight, (1–)2–4 mm.

arcuate, 1.5–2 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, exserted, yellowish green, obloid, weakly striate, concealed in awns, exothecial cells thin-walled, annulus present, operculum conical to rostellate, peristome teeth orange, split distally, papillose.

Calyptra

mitrate.

Grimmia longirostris

Grimmia funalis

Habitat Exposed, dry, acidic granite and quartzite Damp acidic rock
Elevation low to high eleavations (100-3100 m) [low to high eleavations (300-10200 ft)] moderate to high elevations (500-2000 m) [moderate to high elevations (1600-6600 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
LA; MI; NU; ON; Eurasia
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 funalis is frequently misidentified because it is extremely variable in height, color, and length of the awns. In optimal conditions, it forms extremely dense, grayish green cushions that break up easily into clusters and straight single plants. A distinctive feature is the string-like appearance of the dried-up shoots, which results from the spiral twisting of the leaves around the stem. However, Greven has also seen populations without such spirally twisted leaves. Under the microscope, the mid leaf areolation with yellowish, short-rectangular, very thick, and sinuose cell walls is characteristic. The formerly recognized taxa G. calvescens, G. imberbis, and G. ryanii are actually male plants of G. funalis. They grow in separate cushions with muticous to short-awned leaves, deviating greatly from the much taller, long-awned female plants. These male plants might be confused with G. elongata, which frequently grows in the same habitat, or with G. caespiticia. However, in G. elongata the basal cells are pellucid, straight, and thin-walled or only slightly incrassate. In G. caespiticia the basal cells are shorter, tending to be quadrate to short-rectangular, and the leaf apex is cucullate.

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

Source FNA vol. 27, p. 239. FNA vol. 27, p. 251.
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. 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. 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. 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 Trichostomum funale, G. calvescens, G. imberbis, G. ryanii, G. spiralis
Name authority Hooker: Musci Exot. 1: plate 62. (1818) (Schwägrichen) Bruch & Schimper: Bryol. Europ. 3: 119, fig. 247. (1845)
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