Micranthes gaspensis |
Micranthes razshivinii |
|
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Gaspé saxifrage, saxifrage de gaspésie |
large-petal saxifrage, razshivin's saxifrage |
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Habit | Plants solitary or tufted, from caudex. | Plants solitary or in clusters, rhizomatous. |
Leaves | basal; petiole flattened, 0.7–2.5 cm; blade obtrullate or obovate to ovate, 0.8–2.5 cm, ± coriaceous, base attenuate to ± cuneate, margins serrate to dentate on distal 2/3, ciliate, surfaces tangled, reddish brown-hairy abaxially, glabrous or glabrate adaxially. |
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. |
Inflorescences | 3–10-flowered, subcapitate to spicate cymes or thyrses, 2–10(–15) cm, glabrate to sparsely hairy proximally, ± densely purple-tipped stipitate-glandular distally. |
(2–)4–16-flowered, open, racemiform, sometimes paniculiform thyrses, sometimes solitary flowers, 3–15.5(–17 in fruit) cm, glabrous; (bracts reduced). |
Flowers | sepals erect, reflexed in fruit, triangular to deltate; petals white, not spotted, obovate, clawed, 1.5–2 mm, ± equaling sepals; filaments linear, flattened; pistils connate to 1/2 their lengths; ovary 1/2 inferior, appearing more superior in fruit. |
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. |
Capsules | green, becoming reddish or purplish, folliclelike. |
dark purple-black, valvate. |
2n | = 40. |
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Micranthes gaspensis |
Micranthes razshivinii |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | North- or west-facing, abrupt schist slopes, cliff bases, mossy or muddy areas, streamsides, seepages, cool ravines or chimneys | Tundra, stream banks, alpine rocky slopes |
Elevation | 800-1100 m (2600-3600 ft) | 400-2000 m (1300-6600 ft) |
Distribution |
QC |
AK; NT; YT |
Discussion | Of conservation concern. Micranthes gaspensis appears to be the stabilized hybrid derivative of M. nivalis and M. tenuis (C. Gervais et al. 1995), known only from the Shickshock Mountains of the Gaspé Peninsula; the chromosome number is intermediate between that of the parents (2n = 60 and 20, respectively), and seeds are fertile. Neither parent occurs any longer in the Gaspé Peninsula, and the plants appear to self-perpetuate. F1 hybrids of the two parent species (also 2n = 40) occur in Yukon (D. L. Krause and K. I. Beamish 1973) and possibly at other locations throughout their range of sympatry, such as northern Quebec and Labrador; such hybrids will key out with Micranthes gaspensis. Individuals called Saxifraga rufopilosa (Hultén) A. E. Porsild [S. nivalis (Linnaeus) Small var. rufopilosa Hultén] from Yukon and Alaska (W. J. Cody 2000) also will key out here. These may represent either the F1 hybrids mentioned above or stabilized hybrid populations such as those in the Gaspé. It is possible that such stabilized populations would fit under the name M. gaspensis. A systematic study is needed before a taxonomic conclusion can be reached concerning their status. (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.) |
Source | FNA vol. 8, p. 65. | FNA vol. 8, p. 59. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Saxifraga gaspensis | Saxifraga razshivinii |
Name authority | (Fernald) Small: in N. L. Britton et al., N. Amer. Fl. 22: 552. 1918 , | (Zhmylev) Brouillet & Gornall: J. Bot. Res. Inst. Texas 1: 1021. (2007) |
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