Micranthes gaspensis |
Micranthes texana |
|
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Gaspé saxifrage, saxifrage de gaspésie |
Texas saxifrage |
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Habit | Plants solitary or tufted, from caudex. | Plants solitary or in clumps, with bulbils on caudices. |
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 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 | 3–10-flowered, subcapitate to spicate cymes or thyrses, 2–10(–15) cm, glabrate to sparsely hairy proximally, ± densely purple-tipped stipitate-glandular distally. |
20+-flowered, branched, ± capitate thyrses, 10–15 cm, hairy, sometimes purple-tipped stipitate-glandular. |
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 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, becoming reddish or purplish, folliclelike. |
reddish to purplish, valvate. |
2n | = 40. |
|
Micranthes gaspensis |
Micranthes texana |
|
Phenology | Flowering summer. | Flowering late winter–spring. |
Habitat | North- or west-facing, abrupt schist slopes, cliff bases, mossy or muddy areas, streamsides, seepages, cool ravines or chimneys | Sandy flats, rocky, open, wooded areas, granite outcrops |
Elevation | 800-1100 m (2600-3600 ft) | 50-500 m (200-1600 ft) |
Distribution |
QC |
AR; GA; KS; LA; MO; OK; TX |
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.) |
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Source | FNA vol. 8, p. 65. | FNA vol. 8, p. 68. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Saxifraga gaspensis | Saxifraga texana |
Name authority | (Fernald) Small: in N. L. Britton et al., N. Amer. Fl. 22: 552. 1918 , | (Buckley) Small: Fl. S.E. U.S., 501. 1903 , |
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