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Michaux's saxifrage

eastern swamp saxifrage, marsh, marsh saxifrage, Pennsylvania, Pennsylvania saxifrage, swamp saxifrage, swamp small-flower-saxifrage

Habit Plants solitary or tufted, with bulbils on caudices. Plants solitary or in groups, with thick, fleshy rhizomes.
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 indistinct, flattened, 3–10 cm;

blade linear or elliptic to ovate, 6–25 cm, fleshy, base attenuate, margins entire or subentire, ciliate, surfaces usually densely short-hairy, often tangled brown-hairy along proximal midveins.

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).

(30–)50+-flowered, open, often lax thyrses, 25–125 cm, purple-tipped stipitate-glandular.

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 reflexed, triangular to ovate;

petals white to cream or rarely purple, not spotted, linear to narrowly elliptic, not clawed or slightly clawed, 2–3 mm, longer than sepals;

filaments linear, flattened;

pistils connate to 1/2 their lengths;

ovary 1/2+ inferior, appearing superior in fruit.

Capsules

green to yellow, sometimes purple tinged, valvate

green, folliclelike.

2n

= 56, 84, 112.

Micranthes petiolaris

Micranthes pensylvanica

Phenology Flowering late spring–early autumn. Flowering spring.
Habitat Wet ledges, boulderfields, and rocky slopes, usually in thin soil over rock Marshy meadows, mucky seepages in woods, swamp forests, montane bogs and seeps
Elevation 500-2100 m (1600-6900 ft) 100-1400 m (300-4600 ft)
Distribution
from FNA
GA; KY; MD; NC; SC; TN; VA; WV
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; DE; IA; IL; IN; KY; MA; MD; ME; MI; MN; MO; NC; NH; NJ; NY; OH; PA; RI; TN; VA; VT; WI; WV; MB; ON; SK
[WildflowerSearch map]
[BONAP county map]
Discussion

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

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

Purple-petalled populations of Micranthes pensylvanica have been known as Saxifraga purpuripetala and are found in Maine, New York, Pennsylvania, and Vermont.

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

Source FNA vol. 8, p. 58. FNA vol. 8, p. 67.
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. 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. 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 pensylvanica, M. pensylvanica var. purpuripetala, Saxifraga forbesii, Saxifraga pensylvanica var. forbesii, Saxifraga pensylvanica subsp. interior, Saxifraga pensylvanica var. purpuripetala, Saxifraga pensylvanica subsp. tenuirostrata, Saxifraga purpuripetala
Name authority (Rafinesque) Bush: Amer. Midl. Naturalist 11: 225. 1928 , (Linnaeus) Haworth: Saxifrag. Enum., 45. (1821)
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