Apocynum androsaemifolium
Sp. Pl. 1: 213. 1753. (as fol. androsaemi)
Herbs 2–10 dm. Stems glabrous or eglandular-pubescent. Leaves drooping or spreading; petiole 3–5 mm, glabrous or pubescent; blade ovate to oblong-lanceolate, (1–)3–6(–9) × (1–)1.5–3(–5) cm, mostly less than 2 times as long as wide, membranous, base rounded to cuneate, margins weakly to strongly revolute, apex acute to rounded, usually apiculate, surfaces glabrous or densely eglandular-pubescent abaxially, glabrous or sparsely eglandular-pubescent adaxially. Inflorescences usually exceeding foliage; peduncle 1–5 cm, glabrous or sparsely pubescent. Pedicels 1.5–7 mm, glabrous or sparsely pubescent. Flowers: calyx lobes broadly to narrowly triangular-ovate to lanceolate, 1.5–2.5 × 0.5–1 mm, glabrous or with a few scattered hairs; corolla pink or white with pink veins, glabrous abaxially and adaxially, tube 4–5 × 3–4 mm, at least 3 times as long as calyx lobes, lobes spreading or recurved, triangular-ovate, 1.5–3 × 0.7–1.2 mm. Follicles 60–150 × 2–3 mm. Seeds 1.5–2 × 0.3–0.5 mm. 2n = 16, 22.
Phenology: Flowering spring–summer; fruiting summer–fall.
Habitat: Hardwood and coniferous forests and woodlands, clearings, mountain canyons, river terraces, old fields, pastures, roadsides.
Elevation: 10–3000 m.
Distribution
Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon, Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Ga., Idaho, Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo., Mexico (Chihuahua, Coahuila).
Discussion
R. E. Woodson Jr. (1930) recognized three varieties of Apocynum androsaemifolium based primarily on minor differences in corolla morphology and leaf pubescence; these varieties are not recognized here.
Selected References
None.