Gaspé saxifrage, saxifrage de Gaspésie

Saxifraga gaspensis Fernald, Rhodora 19: 141. 1917

Plants solitary or tufted, from caudex. 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. 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. 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. Capsules green, becoming reddish or purplish, folliclelike. 2n = 40.

Flowering summer. North- or west-facing, abrupt schist slopes, cliff bases, mossy or muddy areas, streamsides, seepages, cool ravines or chimneys; of conservation concern; 800-1100 m; Que.

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.