36. Micranthes pensylvanica (Linnaeus) Haworth, Saxifrag. Enum. 45. 1821.
Pennsylvania, marsh, or swamp saxifrage
Saxifraga pensylvanica Linnaeus, Sp. Pl. 1: 399. 1753; Micranthes pensylvanica var. purpuripetala (A. M. Johnson) Bush; S. forbesii Vasey; S. pensylvanica var. forbesii (Vasey) Engler & Irmscher; S. pensylvanica subsp. interior G. W. Burns; S. pensylvanica var. purpuripetala (A. M. Johnson) Bush; S. pensylvanica subsp. tenuirostrata G. W. Burns; S. purpuripetala A. M. Johnson
Plants solitary or in groups, with thick, fleshy rhizomes. Leaves 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-)50+-flowered, open, often lax thyrses, 25-125 cm, purple-tipped stipitate-glandular. Flowers: 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, folliclelike. 2n = 56, 84, 112.
Flowering spring. Marshy meadows, mucky seepages in woods, swamp forests, montane bogs and seeps; 100-1400 m; Man., Ont., Sask.; Conn., Del., Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis.
Purple-petalled populations of Micranthes pensylvanica have been known as Saxifraga purpuripetala and are found in Maine, New York, Pennsylvania, and Vermont.