Micranthes idahoensis |
Micranthes virginiensis |
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Idaho saxifrage |
early saxifrage, early small-flower-saxifrage, saxifrage de virginie, Virginia saxifrage |
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Habit | Plants solitary or tufted, with bulbils on caudices. | Plants solitary or in clumps, with bulbils on caudices. |
Leaves | basal; petiole flattened, 1–5 cm; blade ovate to elliptic, 1–4 cm, ± fleshy, base attenuate, margins shallowly serrate to dentate (teeth usually to 1 mm), sparsely ciliate, surfaces tangled, reddish brown-hairy abaxially, glabrate adaxially. |
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. |
Inflorescences | 15+-flowered, open thyrses, (flowers ± crowded at tips, becoming more open in fruit), 10–40 cm, purple-tipped stipitate-glandular. |
30+-flowered, (flowers sometimes secund), very open, lax, ± flat-topped thyrses, 6–50 cm, proximally hairy, distally densely purple-tipped stipitate-glandular. |
Flowers | sepals reflexed, ovate to oblong; petals white, with 2 basal yellow spots (often faded when dried), elliptic to ovate, clawed to nearly not clawed, 1–3.5 mm, ± equaling sepals; filaments club-shaped, not petaloid, (equaling petals); pistils distinct almost to base; ovary superior, (to 1/3 adnate to hypanthium). |
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). |
Capsules | green to reddish purple, folliclelike. |
green to purplish, folliclelike. |
2n | = 20. |
= 20 (+ 0–6 supernumeraries), 38. |
Micranthes idahoensis |
Micranthes virginiensis |
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Phenology | Flowering spring–early summer. | Flowering spring. |
Habitat | Open ledges and slopes | Rocky hillsides, cliffs and shaded rock outcrops, stream banks, wooded slopes |
Elevation | 500-2500 m (1600-8200 ft) | 0-1500 m (0-4900 ft) |
Distribution |
ID; MT; OR; WA
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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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Discussion | Micranthes idahoensis appears to hybridize with M. occidentalis where their ranges overlap. Intermediates are abundant in some populations along the Idaho-Montana border and in Montana. This phenomenon may explain the range of filament shapes found in M. occidentalis, from flattened to sightly club-shaped. The issue of the status of M. idahoensis with respect to M. marshallii (D. L. Krause and K. I. Beamish 1972) is best deferred until a thorough study of the whole complex over its entire range is done. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 8, p. 64. | FNA vol. 8, p. 61. |
Parent taxa | Saxifragaceae > Micranthes | Saxifragaceae > Micranthes |
Sibling taxa | ||
Synonyms | Saxifraga idahoensis, Saxifraga marshallii subsp. idahoensis, Saxifraga marshallii var. idahoensis, Saxifraga occidentalis var. idahoensis | Saxifraga virginiensis |
Name authority | (Piper) Brouillet & Gornall: J. Bot. Res. Inst. Texas 1: 1020. 2007 , | (Michaux) Small: Fl. S.E. U.S., 501. 1903 , |
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