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Howell's saxifrage

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

Habit Plants solitary or in groups, with bulbils on caudices. Plants solitary or in groups, with thick, fleshy rhizomes.
Leaves

basal;

petiole flattened, 1–4 cm;

blade oblong to narrowly ovate, 1–2(–3) cm, ± fleshy, base attenuate, margins sharply serrate, eciliate, surfaces sparsely tangled, reddish brown-hairy abaxially, glabrous adaxially.

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

5–10(–20)-flowered, very open, lax, ± flat-topped cymes or thyrses, 5–10(–20) cm, glabrate to sparsely purple-tipped stipitate-glandular; (bracts glabrous).

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

Flowers

sepals strongly reflexed, elliptic, (surfaces glabrous);

petals white, not spotted, obovate to elliptic, clawed, 2.5–4.5 mm, longer than sepals;

filaments linear, flattened;

pistils distinct almost to base;

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

purple, valvate.

green, folliclelike.

2n

= 56, 84, 112.

Micranthes howellii

Micranthes pensylvanica

Phenology Flowering early spring–early summer. Flowering spring.
Habitat Wet, rocky ledges and crevices Marshy meadows, mucky seepages in woods, swamp forests, montane bogs and seeps
Elevation 0-900 m (0-3000 ft) 100-1400 m (300-4600 ft)
Distribution
from FNA
CA; OR
[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

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. 63. 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. 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
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 Saxifraga howellii 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 (Greene) Small: in N. L. Britton et al., N. Amer. Fl. 22: 140. (1905) (Linnaeus) Haworth: Saxifrag. Enum., 45. (1821)
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