Micranthes petiolaris |
Micranthes lyallii |
|
---|---|---|
Michaux's saxifrage |
Lyall's saxifrage, red-stem saxifrage |
|
Habit | Plants solitary or tufted, with bulbils on caudices. | Plants solitary or sometimes mat-forming, rhizomatous. |
Leaves | basal; petiole somewhat flattened, 2–6 cm; blade oblanceolate, 2–12 cm, thin, basecuneate to ± attenuate, margins usually 15+-toothed (teeth large, lobelike), densely long glandular-ciliate, surfaces hairy. |
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. |
Inflorescences | 30+-flowered, very open, lax thyrses, (flowers rarely replaced by bulbils), 10–40 cm, densely tangled, purple-tipped stipitate-glandular; (bracts leaflike, gradually reduced distally). |
usually 10–15-flowered, lax, cylindric thyrses, (red), (4–)7–30 cm, sparsely purple-tipped stipitate-glandular. |
Flowers | slightly bilaterally symmetric; sepals reflexed, oblong to elliptic; petals white, 3 with 2 basal yellow spots, 2 without spots, oblanceolate to spatulate, clawed, 3–4.5 mm, longer than sepals; filaments linear, flattened; pistils connate 1/2+ their lengths; ovary superior. |
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). |
Capsules | green to yellow, sometimes purple tinged, valvate |
green to yellow, distal 1/2 purple, ± folliclelike, (basally connate). |
2n | = ca. 56, 58. |
|
Micranthes petiolaris |
Micranthes lyallii |
|
Phenology | Flowering late spring–early autumn. | Flowering summer–early autumn. |
Habitat | Wet ledges, boulderfields, and rocky slopes, usually in thin soil over rock | Wet, rocky meadows, mountain to alpine streamsides |
Elevation | 500-2100 m (1600-6900 ft) | 800-4000 m (2600-13100 ft) |
Distribution |
GA; KY; MD; NC; SC; TN; VA; WV
|
AK; ID; MT; WA; AB; BC; NT; YT
|
Discussion | Micranthes petiolaris (Rafinesque) Brouillet & Gornall is an isonym. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 8, p. 58. | FNA vol. 8, p. 57. |
Parent taxa | Saxifragaceae > Micranthes | Saxifragaceae > Micranthes |
Sibling taxa | ||
Synonyms | Hexaphoma petiolaris, Saxifraga michauxii, Saxifraga petiolaris | Saxifraga lyallii, Saxifraga lyallii subsp. hultenii, Saxifraga lyallii var. hultenii |
Name authority | (Rafinesque) Bush: Amer. Midl. Naturalist 11: 225. 1928 , | (Engler) Small: in N. L. Britton et al., N. Amer. Fl. 22: 143. 1905 , |
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