Herbs, perennial, rhizomatous. Stems simple to highly branched. Leaves numerous, sessile; blade elliptic to ovate, base rounded to cordate-clasping, apex acute to acuminate. Inflorescences 1-2-flowered, peduncle slender, adnate to stem for 1 internode and arising opposite next leaf axil, junction with pedicel abrupt or not, entire structure recurved. Flowers small, borne beneath leaves; perianth rotate or campanulate; tepals deciduous, erect to spreading or recurved, distinct, white to greenish yellow to rose, oblanceolate to oblong; stamens hypogynous; filaments short, broad, flat; anthers basifixed, apex minutely apiculate or with tapering, setose points, extrorse; ovary superior, 3-locular; style slender to bulbous; stigma unlobed or 3-lobed; pedicel geniculate. Fruits baccate, orangish to dark red, ellipsoid to globose. Seeds pale yellow, elongate, grooved longitudinally. x = 8. Streptopus ×oreopolus Fernald (as species) is a sterile hybrid (2n = 24) between S. amplexifolius and S. lanceolatus, and is found in subalpine woods and meadows in glaciated areas of Newfoundland, eastern Quebec, western Ontario, Maine, and New Hampshire (D. Löve and H. Harries 1963; C. Gervais 1979). Its characteristics are intermediate between those of the parent species, except that the leaves are distinctly ciliate-denticulate, the tepals are roseate to deep purple overall, and the berries are deep red.
Perianth campanulate to rotate, the tep separate, essentially alike but the outer whorl usually slightly the wider; stamens 6, adnate to the base of the tep; filaments widened at base; anthers oblong to linear, apiculate or aristate; ovary 3- locular with many ovules; style slender (in our spp.), 3-cleft to entire; fr a red, ellipsoid to globose, many seeded berry; rhizomatous herbs, often branched, with alternate, sessile or clasping lvs and small, greenish-white to pink, purple, or dark red, solitary or paired axillary fls, the axillary peduncle adnate to the stem over the next internode above its origin, with the free part jointed or geniculate well above its base. 10, Eurasia and N. Amer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.