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.
n temperate North America and Eurasia.
Species 7 (3 in the flora).
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.
|1||Stems simple, 1–2 dm; perianth rotate; tepals 3–5 mm; anther apex minutely apiculate; style bulbous-conical, 0.5 mm.||Streptopus streptopoides|
|1||Stems often branched, 1.5–12 dm; perianth campanulate; tepals 6–15 mm; anther apex long-pointed; style slender or stout, 3.5–5 mm.||> 2|
|2||Stems simple or occasionally branched, 1.5–4(–8) dm; leaf base rounded; pedicel rarely geniculate at junction with peduncle, pubescent; tepals slightly spreading, streaked or spotted with pale rose to reddish purple; anthers 2 mm, apex 2-pointed; stigma weakly 3-lobed.||Streptopus lanceolatus|
|2||Stems freely branched, 5–12 dm; leaf base cordate-clasping; pedicel sharply geniculate at junction with peduncle, glabrous; tepals spreading, recurved at tips, whitish to greenish yellow; anthers 3–3.5 mm, apex 1-pointed; stigma fused from base to tip, unlobed.||Streptopus amplexifolius|