Micranthes lyallii |
Micranthes razshivinii |
Micranthes texana |
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Lyall's saxifrage, red-stem saxifrage |
large-petal saxifrage, razshivin's saxifrage |
Texas saxifrage |
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Habit | Plants solitary or sometimes mat-forming, rhizomatous. | Plants solitary or in clusters, rhizomatous. | Plants solitary or in clumps, with bulbils on caudices. |
Leaves | basal; petiole rounded to flattened, 2–10 cm; blade spatulate to obovate, 0.8–8 cm, thin, base cuneate to slightly attenuate, margins serrate to dentate, eciliate or sparsely glandular-ciliate, surfaces abaxially glabrous, adaxially sparsely brown-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. |
basal; petiole flattened, 1–3 cm; blade broadly ovate to oblong, 1.5–3 cm, ± leathery, base ± abruptly attenuate, margins subentire to slightly crenate, eciliate, surfaces glabrate to sparsely hairy. |
Inflorescences | usually 10–15-flowered, lax, cylindric thyrses, (red), (4–)7–30 cm, sparsely purple-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). |
20+-flowered, branched, ± capitate thyrses, 10–15 cm, hairy, sometimes purple-tipped stipitate-glandular. |
Flowers | sepals reflexed, oblong to elliptic; petals white, each with 2 basal yellowish green spots, elliptic to round, clawed, 2–5.5 mm, longer than sepals; filaments club-shaped, (to 6 mm); pistils connate 1/2+ 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. |
sepals erect, ovate; petals white, not spotted, ± obovate, clawed, 2–3.5 mm, ± equaling sepals; filaments linear, flattened; pistils 3+, connate to 1/2 their lengths; ovary 1/2+ inferior, appearing more superior in fruit. |
Capsules | green to yellow, distal 1/2 purple, ± folliclelike, (basally connate). |
dark purple-black, valvate. |
reddish to purplish, valvate. |
2n | = ca. 56, 58. |
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Micranthes lyallii |
Micranthes razshivinii |
Micranthes texana |
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Phenology | Flowering summer–early autumn. | Flowering summer. | Flowering late winter–spring. |
Habitat | Wet, rocky meadows, mountain to alpine streamsides | Tundra, stream banks, alpine rocky slopes | Sandy flats, rocky, open, wooded areas, granite outcrops |
Elevation | 800-4000 m (2600-13100 ft) | 400-2000 m (1300-6600 ft) | 50-500 m (200-1600 ft) |
Distribution |
AK; ID; MT; WA; AB; BC; NT; YT
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AK; NT; YT |
AR; GA; KS; LA; MO; OK; TX |
Discussion | Although they have nearly disjunct sets of populations, the subspecies of Micranthes lyallii are difficult to distinguish from each other. The more northern plants tend to be larger with wider leaves and often have been called Saxifraga lyallii subsp. or var. hultenii. Apparent hybrids with M. odontoloma occur in Alberta, British Columbia, and northern Idaho, and near Glacier National Park, Montana. (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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Source | FNA vol. 8, p. 57. | FNA vol. 8, p. 59. | FNA vol. 8, p. 68. |
Parent taxa | Saxifragaceae > Micranthes | Saxifragaceae > Micranthes | Saxifragaceae > Micranthes |
Sibling taxa | |||
Synonyms | Saxifraga lyallii, Saxifraga lyallii subsp. hultenii, Saxifraga lyallii var. hultenii | Saxifraga razshivinii | Saxifraga texana |
Name authority | (Engler) Small: in N. L. Britton et al., N. Amer. Fl. 22: 143. 1905 , | (Zhmylev) Brouillet & Gornall: J. Bot. Res. Inst. Texas 1: 1021. (2007) | (Buckley) Small: Fl. S.E. U.S., 501. 1903 , |
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