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Michaux's saxifrage

Gaspé saxifrage, saxifrage de gaspésie

Habit Plants solitary or tufted, with bulbils on caudices. Plants solitary or tufted, from caudex.
Leaves

basal;

petiole somewhat flattened, 2–6 cm;

blade oblanceolate, 2–12 cm, thin, basecuneate to ± attenuate, margins usually 15+-toothed (teeth large, lobelike), densely long glandular-ciliate, surfaces hairy.

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

30+-flowered, very open, lax thyrses, (flowers rarely replaced by bulbils), 10–40 cm, densely tangled, purple-tipped stipitate-glandular; (bracts leaflike, gradually reduced distally).

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

slightly bilaterally symmetric;

sepals reflexed, oblong to elliptic;

petals white, 3 with 2 basal yellow spots, 2 without spots, oblanceolate to spatulate, clawed, 3–4.5 mm, longer than sepals;

filaments linear, flattened;

pistils connate 1/2+ their lengths;

ovary superior.

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 to yellow, sometimes purple tinged, valvate

green, becoming reddish or purplish, folliclelike.

2n

= 40.

Micranthes petiolaris

Micranthes gaspensis

Phenology Flowering late spring–early autumn. Flowering summer.
Habitat Wet ledges, boulderfields, and rocky slopes, usually in thin soil over rock North- or west-facing, abrupt schist slopes, cliff bases, mossy or muddy areas, streamsides, seepages, cool ravines or chimneys
Elevation 500-2100 m (1600-6900 ft) 800-1100 m (2600-3600 ft)
Distribution
from FNA
GA; KY; MD; NC; SC; TN; VA; WV
[WildflowerSearch map]
[BONAP county map]
from FNA
QC
[BONAP county map]
Discussion

Micranthes petiolaris (Rafinesque) Brouillet & Gornall is an isonym.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

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.)

Source FNA vol. 8, p. 58. FNA vol. 8, p. 65.
Parent taxa Saxifragaceae > Micranthes Saxifragaceae > Micranthes
Sibling taxa
M. apetala, M. aprica, M. bryophora, M. californica, M. calycina, M. careyana, M. caroliniana, M. eriophora, M. ferruginea, M. foliolosa, M. fragosa, M. gaspensis, M. gormanii, M. hieraciifolia, M. hitchcockiana, M. howellii, M. idahoensis, M. integrifolia, M. lyallii, M. marshallii, M. micranthidifolia, M. nelsoniana, M. nidifica, M. nivalis, M. nudicaulis, M. occidentalis, M. odontoloma, M. oregana, M. palmeri, M. pensylvanica, M. razshivinii, M. reflexa, M. rhomboidea, M. rufidula, M. spicata, M. stellaris, M. subapetala, M. tempestiva, M. tenuis, M. texana, M. tischii, M. tolmiei, M. unalaschcensis, M. virginiensis
M. apetala, M. aprica, M. bryophora, M. californica, M. calycina, M. careyana, M. caroliniana, M. eriophora, M. ferruginea, M. foliolosa, M. fragosa, M. gormanii, M. hieraciifolia, M. hitchcockiana, M. howellii, M. idahoensis, M. integrifolia, M. lyallii, M. marshallii, M. micranthidifolia, M. nelsoniana, M. nidifica, M. nivalis, M. nudicaulis, M. occidentalis, M. odontoloma, M. oregana, M. palmeri, M. pensylvanica, M. petiolaris, M. razshivinii, M. reflexa, M. rhomboidea, M. rufidula, M. spicata, M. stellaris, M. subapetala, M. tempestiva, M. tenuis, M. texana, M. tischii, M. tolmiei, M. unalaschcensis, M. virginiensis
Synonyms Hexaphoma petiolaris, Saxifraga michauxii, Saxifraga petiolaris Saxifraga gaspensis
Name authority (Rafinesque) Bush: Amer. Midl. Naturalist 11: 225. 1928 , (Fernald) Small: in N. L. Britton et al., N. Amer. Fl. 22: 552. 1918 ,
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