Micranthes californica |
Micranthes tenuis |
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California saxifrage, Greene's saxifrage |
slender saxifrage |
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Habit | Plants solitary or in clumps, with bulbils on caudices, or rhizomatous. | Plants tufted, with bulbils on caudices. |
Leaves | basal; petiole flattened, 2–5 cm; blade ovate, 2–7 cm, fleshy, base attenuate, margins serrate, rarely subentire, ciliate, surfaces hairy. |
basal; petiole broad, flattened, 0.2–1 cm; blade ± obovate to ± obtrullate, 0.5–1.5 cm, ± coriaceous, base ± attenuate to ± cuneate, margins serrate to dentate on distal 1/3–2/3, sometimes ciliate, surfaces glabrous or glabrate abaxially (rarely sparsely reddish brown-hairy). |
Inflorescences | 20+-flowered, (flowers often secund), open, lax thyrses with distant lateral branches, 15–30(–40) cm, purple-tipped stipitate-glandular. |
usually 2–10-flowered, ± capitate cymes, sometimes solitary flowers, (1–)2–7(–11) cm, hairy or glabrous proximally, glabrate or ± purple-tipped stipitate-glandular distally. (Pedicels proximal ± elongate.) Flowers: sepals erect, ovate to deltate; petals white with purple margins, usually pink or purple tinged, not spotted, obovate to oblong, clawed, 2–3 mm, usually slightly longer than sepals; filaments linear, flattened; pistils connate to 1/2 their lengths; ovary 1/2 inferior, appearing more superior in fruit. |
Flowers | sepals reflexed, sometimes spreading, triangular to ovate; petals white, not spotted, elliptic to oblong, clawed, 2.5–4.5 mm, longer than sepals; filaments linear, flattened; pistils connate to 1/2 their lengths; ovary 1/2+ inferior, appearing superior in fruit. |
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Capsules | purplish, folliclelike. |
reddish to purplish, folliclelike. |
2n | = 20. |
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Micranthes californica |
Micranthes tenuis |
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Phenology | Flowering winter–early spring. | Flowering summer. |
Habitat | Shaded fields, rocky or unstable slopes, stream banks | Open, mossy tundra, rocky ridges, shady ledges |
Elevation | 0-1500 m (0-4900 ft) | 0-1500 m (0-4900 ft) |
Distribution |
CA; OR; Mexico (Baja California)
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AK; BC; LB; NT; NU; QC; YT; Greenland; Europe; Asia (Siberia) |
Discussion | Micranthes tenuis is morphologically distinguished from M. nivalis only with great difficulty. D. A. Webb and R. J. Gornall (1989) claimed that chromosome number is one of the chief reasons for continuing to recognize the species and, indeed, their enumeration of morphologic differences is not entirely convincing. Occasionally, both species appear to occur in the same populations. The generally smaller size, tendency to glabrousness, fewer number of flowers, and petal color variations reasonably distinguish M. tenuis. Depauperate specimens of M. nivalis are particularly difficult to separate from M. tenuis except for their very consistent hairiness and white petals. Due to the morphologic confusion, exact distributions are difficult to assess and chromosome number reports may be doubtful (D. L. Krause and K. I. Beamish 1973). A thorough systematic study is needed. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 8, p. 64. | FNA vol. 8, p. 65. |
Parent taxa | Saxifragaceae > Micranthes | Saxifragaceae > Micranthes |
Sibling taxa | ||
Synonyms | Saxifraga californica, M. parvifolia, Saxifraga fallax, Saxifraga hallii, Saxifraga parvifolia, Saxifraga virginiensis var. californica | Saxifraga nivalis var. tenuis, Saxifraga tenuis |
Name authority | (Greene) Small: in N. L. Britton et al., N. Amer. Fl. 22: 140. (1905) | (Wahlenberg) Small: in N. L. Britton et al., N. Amer. Fl. 22: 136. (1905) |
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