Orthotrichum laevigatum |
Orthotrichum pellucidum |
|
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orthotrichum moss |
xerophytic limestone moss |
|
Habit | Plants (0.5–)2(–4.3) cm, light green to olive green. | Plants to 2.5 cm, appearing glaucous. |
Stem | leaves stiff, erect-appressed, slightly secund when dry, oblong-lanceolate, lanceolate, or ovate-lanceolate, 2–4.3 mm; margins revolute from base to near apex, entire; apex obtuse, bluntly or narrowly acute, or gradually acuminate; basal laminal cells rectangular to elongate, grading to elliptic-quadrate, walls thick, nodose; distal cells 8–12 µm, 1-stratose, papillae 1–3 per cell, conic or 2-fid, low. |
leaves stiff, closely erect-appressed, incurved when dry, oblong-lanceolate or lanceolate, 2–2.7 mm; margins recurved proximally, reflexed distally, entire; apex blunt or obtuse; basal laminal cells short-rectangular to quadrate, grading to subquadrate at margin, walls thin, not nodose; distal cells 6–11 µm, 1-stratose, papillae 1–3 per cell, conic or 2-fid, large. |
Seta | 1.5–4 mm. |
1–1.5 mm. |
Sexual condition | gonioautoicous. |
gonioautoicous. |
Capsule | fully exserted, cylindric, 1.4–2.6 mm, smooth or sometimes slightly plicate distally; exothecial cells homogeneous; stomata superficial; peristome double; prostome absent or rudimentary; exostome teeth 16, erect, papillose; endostome segments 8, occasionally rudimentary, usually absent in open capsules, of 1 row of cells, smooth. |
1/2 emergent to short-exserted, oblong-ovate to ovate when mature, oblong to short-oblong when old and dry, 1.2–1.9 mm, strongly 8-ribbed entire length, rarely 16-ribbed with 8 short intermediate ribs, constricted below mouth when dry; stomata immersed; peristome single; prostome rudimentary; exostome teeth usually 16 when mature, irregularly split, often absent when capsule is old, erect or spreading, papillose-striate to coarsely reticulate-papillose; endostome segments absent. |
Calyptra | conic-oblong, smooth, sparsely hairy, hairs finely papillose. |
oblong, smooth, hairy, hairs papillose. |
Spores | 10–15 µm. |
10–15 µm. |
Specialized | asexual reproduction absent. |
asexual reproduction absent. |
Orthotrichum laevigatum |
Orthotrichum pellucidum |
|
Habitat | Non-calcareous boulders in mesic, open coniferous forests, base of deciduous trees | Calcareous or siliceous boulders, cliff faces in xeric areas, direct sunlight |
Elevation | moderate to high elevations (500-3000 m) (moderate to high elevations (1600-9800 ft)) | moderate to high elevations (500- 3000 m) (moderate to high elevations (1600- 9800 ft)) |
Distribution |
AK; AZ; CA; CO; ID; MT; NV; OR; SD; UT; WA; WY; AB; BC; MB; NT; SK; YT; Europe; e Asia (Japan)
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AK; AZ; CA; CO; ID; MT; NM; NV; OR; SD; UT; WY; AB; BC; MB; NT; NU; YT; Greenland; n Europe |
Discussion | Orthotrichum laevigatum is part of a complex group of intergrading taxa that generally are characterized by exserted, cylindric capsules with 16 erect or reflexed exostome teeth and a poorly developed endostome. Gametophytically, robust plants have stiff, erect leaves and large, blunt papillae. This complex is treated here as three species: O. holzingeri, a distinct, highly specialized species of seasonally wet rock with smooth exostome teeth, smooth laminal cells, smooth calyptra, and slightly ribbed capsule as distinguishing features; O. laevigatum, distinguished by smooth capsule and erect, papillose exostome teeth; and O. pylaisii, distinguished by slightly 8-ribbed capsule and reflexed-recurved exostome teeth. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Orthotrichum pellucidum is distinguished by its blunt, lanceolate-oblong leaves that always appear glaucous because of the large 2-fid papillae of the distal laminal cells. When the plants are fertile, which is usually the case, the short-exserted, oblong-ovate, 8-ribbed capsules identify O. pellucidum. The capsule has stomata in the proximal to mid capsule, more or less covered by projecting subsidiary cells. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 28, p. 57. | FNA vol. 28, p. 62. |
Parent taxa | Orthotrichaceae > Orthotrichum | Orthotrichaceae > Orthotrichum |
Sibling taxa | ||
Synonyms | O. hainesiae, O. kingianum, O. laevigatum var. kingianum, O. lonchothecium, O. macounii, O. macounii var. lonchothecium, O. raui, O. roellii, O. roellii subsp. schlotthaueri, O. roellii subsp. stenocarpum, O. schlotthaueri, O. speciosum var. brevicaule, O. speciosum var. hainesiae, O. speciosum subsp. laevigatum, O. speciosum var. polyanthum, O. speciosum var. polycarpum, O. speciosum var. raui | O. cupulatum var. jamesianum, O. jamesianum |
Name authority | J. E. Zetterstedt: Öfvers. Kongl. Vetensk.-Akad. Förh. 19: 363. (1862) | Lindberg: Öfvers. Kongl. Vetensk.-Akad. Förh. 23: 549. (1867) |
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