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orthotrichum moss, rock bristle-moss

orthotrichum moss

Habit Plants (1–)3–12.5 cm, light green to olive green. Plants 0.3–1 cm.
Stem

leaves stiff, erect-appressed when dry, narrowly lanceolate to ovate-lanceolate, 2–4.5 mm;

margins recurved to narrowly revolute to near apex, entire;

apex sharply to slenderly acute;

basal laminal cells elongate to rectangular, walls thick, ± nodose;

distal cells 6–13 µm, 1-stratose, papillae 1 or 2 per cell, conic and small, or 2-fid and low.

leaves erect-appressed when dry, oblong-lanceolate to oblong, 0.7–1.3 mm;

margins reflexed to broadly recurved, entire;

apex rounded-obtuse;

basal laminal cells elongate, walls thick, ± nodose;

distal cells 7–13 µm, 1-stratose, papillae 1 or 2 per cell, conic or C-shaped, small.

Seta

to 1.8 mm.

to 5 mm.

Sexual condition

gonioautoicous.

gonioautoicous.

Capsule

immersed, emergent, or slightly exserted, usually 1/3 emergent, globose ovate, ovate-oblong, or short-oblong, 1.3–1.8 mm, slightly or distinctly 8-ribbed 1/2–2/3 length;

stomata superficial;

peristome single, rarely double;

prostome large, conspicuous, or rudimentary;

exostome teeth 16, erect or sometimes spreading-recurved when old, smooth, scattered-papillose, or coarsely papillose-granulate;

endostome segments absent, or rarely 8, rudimentary, of 1 row of cells, smooth or roughened.

immersed or slightly emergent, ovate-oblong, widest at mouth, less than 1 mm, distinctly 8-ribbed to base when dry;

stomata superficial;

peristome double;

prostome absent;

exostome teeth 16, spreading or reflexed when dry, papillose to cross striolate proximally, papillose to vertically or reticulately striolate distally;

endostome segments 8, well developed, usually present when capsule is old and dry, thick, delicate, of 2 rows of cells, as wide as exostome teeth, hyaline, granulate-papillose.

Calyptra

oblong, smooth, hairy or rarely naked, hairs finely papillose.

short-conic, finely papillose, naked or hairs few near tip, hairs finely papillose.

Spores

13–21 µm.

17–20 µm.

Specialized

asexual reproduction absent.

asexual reproduction by gemmae on leaves.

Orthotrichum rupestre

Orthotrichum exiguum

Habitat Non-calcareous boulders and cliff faces in mesic areas of pine, spruce-fir, or aspen forests, base of trees, subalpine shade Base and trunks of trees
Elevation low to high elevations (100-3000 m) (low to high elevations (300-9800 ft)) low to moderate elevations (10-200 m) (low to moderate elevations (0-700 ft))
Distribution
from FNA
AK; AZ; CA; CO; ID; MT; NM; NV; OR; SD; UT; WA; WY; AB; BC; NT; NU; ON; YT; South America; e Africa; Pacific Islands (New Zealand); Atlantic Islands (Canary Islands); Greenland; n Africa; e Asia (Japan); Europe; Australia
[WildflowerSearch map]
from FNA
GA; NC; SC; TN; VA; e Asia
Discussion

In typical form, Orthotrichum rupestre is characterized as much-branched plants in loose tufts with lanceolate leaves, apex narrowly and bluntly acute, basal cells elongate, thick-walled, and nodose, yellowish in older leaves, capsule oblong, emergent, 8-ribbed to mid capsule when old and dry, smooth or slightly 8-ribbed when mature, exostome of 16 erect teeth, coarsely papillose, and calyptra with abundant, spinulose, papillose hairs, some of which extend over the beak.

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

Orthotrichum exiguum is distinguished by the distal laminal cells with bulging walls and C-shaped papillae; clavate stems; papillose, quadrate basal cells; differentiated perichaetial leaves; and capsules that are widest at the mouth, with 16 reflexed exostome teeth and delicate hyaline endostome.

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

Source FNA vol. 28, p. 65. FNA vol. 28, p. 55.
Parent taxa Orthotrichaceae > Orthotrichum Orthotrichaceae > Orthotrichum
Sibling taxa
O. affine, O. alpestre, O. anodon, O. anomalum, O. bartramii, O. bolanderi, O. consimile, O. cupulatum, O. diaphanum, O. elegans, O. euryphyllum, O. exiguum, O. fenestratum, O. flowersii, O. gymnostomum, O. hallii, O. holzingeri, O. keeverae, O. kellmanii, O. laevigatum, O. lescurii, O. lyellii, O. norrisii, O. obtusifolium, O. ohioense, O. pallens, O. parvulum, O. pellucidum, O. praemorsum, O. pulchellum, O. pumilum, O. pusillum, O. pycnophyllum, O. pylaisii, O. rivulare, O. shawii, O. shevockii, O. sordidum, O. speciosum, O. spjutii, O. stellatum, O. stramineum, O. strangulatum, O. striatum, O. tenellum, O. underwoodii
O. affine, O. alpestre, O. anodon, O. anomalum, O. bartramii, O. bolanderi, O. consimile, O. cupulatum, O. diaphanum, O. elegans, O. euryphyllum, O. fenestratum, O. flowersii, O. gymnostomum, O. hallii, O. holzingeri, O. keeverae, O. kellmanii, O. laevigatum, O. lescurii, O. lyellii, O. norrisii, O. obtusifolium, O. ohioense, O. pallens, O. parvulum, O. pellucidum, O. praemorsum, O. pulchellum, O. pumilum, O. pusillum, O. pycnophyllum, O. pylaisii, O. rivulare, O. rupestre, O. shawii, O. shevockii, O. sordidum, O. speciosum, O. spjutii, O. stellatum, O. stramineum, O. strangulatum, O. striatum, O. tenellum, O. underwoodii
Synonyms Dorcadion rupestre, O. bullatum, O. californicum, O. douglasii, O. macfaddenae, O. rupestre var. globosum, O. rupestre var. macfaddenae, O. texanum, O. texanum var. globosum
Name authority Schleicher ex Schwagrichen: Sp. Musc. Frond. Suppl. 1(2): 27, plate 53 [top]. (1816) Sullivant: in A. Gray, Manual ed. 2, 633. (1856)
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