Micranthes virginiensis |
Micranthes occidentalis |
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early saxifrage, early small-flower-saxifrage, saxifrage de virginie, Virginia saxifrage |
mountain saxifrage, redwool saxifrage, western saxifrage |
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Habit | Plants solitary or in clumps, with bulbils on caudices. | Plants in groups or sometimes almost mat-forming, with bulbils on caudices or rhizomatous. |
Leaves | basal; petiole flattened, 1–9 cm; blade ovate to elliptic, 2–8 cm, ± fleshy, base attenuate, margins irregularly crenate to serrate, ciliate, surfaces sparsely to ± densely stipitate-glandular and tangled, reddish brown-hairy, adaxially glabrescent. |
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. |
Inflorescences | 30+-flowered, (flowers sometimes secund), very open, lax, ± flat-topped thyrses, 6–50 cm, proximally hairy, distally densely purple-tipped stipitate-glandular. |
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). |
Flowers | sepals erect to ascending (even in fruit), ovate to triangular; petals white, not spotted, broadly oblong to elliptic, not or rarely slightly clawed, 3–6 mm, 2+ times as long as sepals; filaments linear, flattened; pistils distinct almost to base; ovary ± superior, (to 1/3 adnate hypanthium). |
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. |
Capsules | green to purplish, folliclelike. |
greenish or reddish to ± dark purple, folliclelike. |
2n | = 20 (+ 0–6 supernumeraries), 38. |
= 20, 38, 40, 56, 58. |
Micranthes virginiensis |
Micranthes occidentalis |
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Phenology | Flowering spring. | Flowering spring–summer. |
Habitat | Rocky hillsides, cliffs and shaded rock outcrops, stream banks, wooded slopes | Wet, rocky or gravelly slopes, moist to dry alpine meadows, flushes |
Elevation | 0-1500 m (0-4900 ft) | 500-4000 m (1600-13100 ft) |
Distribution |
AL; AR; CT; DC; GA; IL; IN; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WV; MB; NB; ON; QC
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AK; ID; MT; NV; OR; SD; WA; WY; AB; BC; SK
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Discussion | Also reported for Micranthes virginiensis is 2n = 28; D. E. Soltis (1983) documented zero to six supernumerary chromosomes in this species and speculated that this report may have included eight supernumeraries. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 8, p. 61. | FNA vol. 8, p. 62. |
Parent taxa | Saxifragaceae > Micranthes | Saxifragaceae > Micranthes |
Sibling taxa | ||
Synonyms | Saxifraga virginiensis | Saxifraga occidentalis, Saxifraga allenii, Saxifraga occidentalis var. allenii, Saxifraga occidentalis var. wallowensis, Saxifraga reflexa subsp. occidentalis, Saxifraga saximontana |
Name authority | (Michaux) Small: Fl. S.E. U.S., 501. 1903 , | (S. Watson) Small: in N. L. Britton et al., N. Amer. Fl. 22: 144. 1905 , |
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