Micranthes occidentalis |
Micranthes howellii |
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mountain saxifrage, redwool saxifrage, western saxifrage |
Howell's saxifrage |
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Habit | Plants in groups or sometimes almost mat-forming, with bulbils on caudices or rhizomatous. | Plants solitary or in groups, with bulbils on caudices. |
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, 1–4 cm; blade oblong to narrowly ovate, 1–2(–3) cm, ± fleshy, base attenuate, margins sharply serrate, eciliate, surfaces sparsely tangled, reddish brown-hairy abaxially, glabrous adaxially. |
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). |
5–10(–20)-flowered, very open, lax, ± flat-topped cymes or thyrses, 5–10(–20) cm, glabrate to sparsely purple-tipped stipitate-glandular; (bracts glabrous). |
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 strongly reflexed, elliptic, (surfaces glabrous); petals white, not spotted, obovate to elliptic, clawed, 2.5–4.5 mm, longer than sepals; filaments linear, flattened; pistils distinct almost to base; ovary ± superior. |
Capsules | greenish or reddish to ± dark purple, folliclelike. |
purple, valvate. |
2n | = 20, 38, 40, 56, 58. |
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Micranthes occidentalis |
Micranthes howellii |
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Phenology | Flowering spring–summer. | Flowering early spring–early summer. |
Habitat | Wet, rocky or gravelly slopes, moist to dry alpine meadows, flushes | Wet, rocky ledges and crevices |
Elevation | 500-4000 m (1600-13100 ft) | 0-900 m (0-3000 ft) |
Distribution |
AK; ID; MT; NV; OR; SD; WA; WY; AB; BC; SK
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CA; OR
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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.) |
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Source | FNA vol. 8, p. 62. | FNA vol. 8, p. 63. |
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 howellii |
Name authority | (S. Watson) Small: in N. L. Britton et al., N. Amer. Fl. 22: 144. 1905 , | (Greene) Small: in N. L. Britton et al., N. Amer. Fl. 22: 140. (1905) |
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