Micranthes occidentalis |
Micranthes integrifolia |
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mountain saxifrage, redwool saxifrage, western saxifrage |
Columbian saxifrage, grassland saxifrage, northwestern saxifrage, smooth leaf saxifrage, swamp saxifrage, whole-leaf saxifrage |
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Habit | Plants in groups or sometimes almost mat-forming, with bulbils on caudices or rhizomatous. | Plants solitary or in clumps, (sometimes gynodioecious), often with bulbils on caudices, or short-rhizomatous. |
Leaves | basal; petiole flattened, 1–5 cm; blade ovate to elliptic, 1.5–3.5 cm, ± fleshy, base ± attenuate to ± truncate, margins shallowly, sharply serrate, ciliate, surfaces sparsely tangled, reddish brown-hairy abaxially, glabrous adaxially. |
basal; petiole flattened, 0.5–4 cm; blade narrowly to broadly ovate, 2–7 cm, ± leathery, base attenuate, margins entire or minutely denticulate, usually ciliate, surfaces sparsely to moderately hairy. |
Inflorescences | usually (10–)30+-flowered, flowers crowded into 1+ glomerules in thyrses with ascending branches, 8–30 cm, purple-tipped stipitate-glandular; (bracts glabrous or marginally glandular-ciliate). |
(15–)20+-flowered, open to ± congested, conic thyrses, (usually branched, lateral cymules ± open), 12–35 cm, densely pink- to purple-tipped stipitate-glandular. |
Flowers | sepals ascending to spreading, sometimes reflexed in fruit, ovate to oblong, (surfaces glabrous); petals white, not spotted (spots rarely present), obovate to almost round, clawed, 2–4 mm, to 1.5 times as long as sepals; filaments linear to very slightly widened near anthers, flattened; pistils distinct almost to base; ovary ± superior. |
sepals spreading to slightly reflexed, ovate; petals white, not spotted, obovate, clawed, 2–4 mm, longer than sepals; filaments linear, flattened; pistils connate to 1/2 their lengths; ovary 1/2+ inferior. |
Capsules | greenish or reddish to ± dark purple, folliclelike. |
reddish or purplish, folliclelike. |
2n | = 20, 38, 40, 56, 58. |
= 38. |
Micranthes occidentalis |
Micranthes integrifolia |
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Phenology | Flowering spring–summer. | Flowering late winter–spring. |
Habitat | Wet, rocky or gravelly slopes, moist to dry alpine meadows, flushes | Vernally moist meadows, grassy slopes, rock outcrops |
Elevation | 500-4000 m (1600-13100 ft) | 0-1800 m (0-5900 ft) |
Distribution |
AK; ID; MT; NV; OR; SD; WA; WY; AB; BC; SK
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CA; OR; WA; BC
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Discussion | Micranthes occidentalis appears closely related to the little-known M. mexicana (Engler & Irmscher) Brouillet & Gornall from Chihuahua, Mexico. The latter is the only species of the genus that occurs in Mexico and not in the United States. Micranthes occidentalis is disjunct between the northern Rocky Mountains and the Cypress Hills of southeastern Alberta and southwestern Saskatchewan, and the Black Hills of South Dakota. It hybridizes with M. idahoensis where their ranges overlap. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The occasional occurrence of sterile pollen has been noted in this as well as in other species of Micranthes (as Saxifraga, K. I. Beamish 1961). Some populations exhibit gynodioecism (P. E. Elvander 1982). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 8, p. 62. | FNA vol. 8, p. 67. |
Parent taxa | Saxifragaceae > Micranthes | Saxifragaceae > Micranthes |
Sibling taxa | ||
Synonyms | Saxifraga occidentalis, Saxifraga allenii, Saxifraga occidentalis var. allenii, Saxifraga occidentalis var. wallowensis, Saxifraga reflexa subsp. occidentalis, Saxifraga saximontana | Saxifraga integrifolia |
Name authority | (S. Watson) Small: in N. L. Britton et al., N. Amer. Fl. 22: 144. 1905 , | (Hooker) Small: in N. L. Britton et al., N. Amer. Fl. 22: 137. 1905 , |
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