Micranthes nelsoniana |
Micranthes razshivinii |
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dotted saxifrage, heartleaf saxifrage, Nelson's saxifrage, saxifrage |
large-petal saxifrage, razshivin's saxifrage |
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Habit | Plants solitary or tufted, with bulbils on branched caudices, rhizomatous. | Plants solitary or in clusters, rhizomatous. | ||||||||||||||||
Leaves | basal; petiole rounded, 3–30 cm; blade reniform to round, 2–9 cm, thin or slightly fleshy, sometimes thick and fleshy, base cordate, margins deeply crenate, eciliate or sparsely short glandular-ciliate, surfaces glabrous or ± hairy. |
basal; petiole ± distinct to indistinct, flattened, (0.3–)0.5–3 cm; blade oblanceolate to narrowly oblanceolate or narrowly spatulate, sometimes ± narrowly obovate, (0.5–)0.9–3.5 cm, ± fleshy, base ± attenuate to cuneate, margins (3–)5–7(–9)-toothed in distal 1/2 (teeth 0.5 mm), sparsely ciliate, surfaces glabrous. |
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Inflorescences | 10+-flowered, ± open, lax to congested, conic, sometimes also glomerate thyrses, 10–35 cm, tangled-hairy (pilose-arachnoid) at least distally, sometimes also purple- or brown-tipped stipitate-glandular. |
(2–)4–16-flowered, open, racemiform, sometimes paniculiform thyrses, sometimes solitary flowers, 3–15.5(–17 in fruit) cm, glabrous; (bracts reduced). |
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Flowers | sepals reflexed, ± ovate; petals white to pinkish, rarely orange-spotted, ovate to oblong, narrowly to broadly clawed, 2.5–4.5 mm, longer than sepals; filaments distinctly club-shaped; pistils connate 1/2–3/4 their lengths; ovary superior (to 1/3 adnate to hypanthium). |
sepals reflexed, oblong or lanceolate to ovate; petals white to cream, often purplish, not spotted, linear to ± narrowly elliptic, not clawed, 2–4 mm, usually longer to sometimes shorter than sepals; filaments linear, flattened; pistils connate 1/2+ their lengths, (conic); ovary ± 1/2 inferior. |
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Capsules | green to yellow and purplish tinged to dark purple, valvate. |
dark purple-black, valvate. |
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Micranthes nelsoniana |
Micranthes razshivinii |
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Phenology | Flowering summer. | |||||||||||||||||
Habitat | Tundra, stream banks, alpine rocky slopes | |||||||||||||||||
Elevation | 400-2000 m (1300-6600 ft) | |||||||||||||||||
Distribution |
AK; OR; WA; AB; BC; NT; NU; YT; Europe (ne Russia); Asia
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AK; NT; YT |
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Discussion | Varieties 6 (5 in the flora). Although sometimes reported for North America, Saxifraga nelsoniana var. aestivalis (Fischer & C. A. Meyer) H. Ohba (S. aestivalis Fischer & C. A. Meyer) is found only in Eurasia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Micranthes razshivinii is found in eastern Alaska (eastern Brooks Range, from Atigun Pass eastward and from Mount McKinley National Park eastward) into Yukon and in the Mackenzie and Richardson mountains in the Northwest Territories. Its leaves are generally narrower than those of M. calycina and the teeth are less numerous. The glabrous inflorescence branches of M. razshivinii readily distinguish it from M. calycina, which has hairy branches. The ranges of the two species may overlap or at least abut in the Atigun Pass area of the Brooks Range, in the Mount McKinley National Park area, and possibly in the Saint Elias Mountains. Hybrids would be very difficult to distinguish from the parents but may occur. They have not been observed in the material examined. Plants of this species sometimes have been misidentified as M. davurica (Willdenow) Small, a species restricted to eastern Siberia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 8, p. 54. | FNA vol. 8, p. 59. | ||||||||||||||||
Parent taxa | Saxifragaceae > Micranthes | Saxifragaceae > Micranthes | ||||||||||||||||
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Synonyms | Saxifraga nelsoniana, Saxifraga punctata subsp. nelsoniana, Saxifraga punctata var. nelsoniana | Saxifraga razshivinii | ||||||||||||||||
Name authority | (D. Don) Small: in N. L. Britton et al., N. Amer. Fl. 22: 147. 1905 , | (Zhmylev) Brouillet & Gornall: J. Bot. Res. Inst. Texas 1: 1021. (2007) | ||||||||||||||||
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