Divine nightshade

Herbs, perennial, erect to somewhat sprawling, unarmed, to 3 m, nearly glabrous to moderately pubescent, hairs unbranched, to 1 mm, eglan­dular. Leaves petiolate; petiole 0.5–2 cm; blade simple, ovate to ovate-elliptic, 4–10.5 × 2–5 cm, margins entire or shallowly sinuate-dentate, base decurrent. Inflorescences extra-axillary or leaf-opposed, unbranched, umbel-like to racemelike, (2–)5–10-flowered, 1–3.5 cm. Pedicels spreading and 0.5–1 cm in flower, spreading and 1–1.5 cm in fruit. Flowers radially symmetric; calyx not accrescent, unarmed, 1–2 mm, sparsely pubescent, lobes deltate; corolla white, rarely purplish, often with green or purplish central star, stellate, 1–1.5 cm diam., with sparse interpetalar tissue; stamens equal; anthers ellip­soidal, 2–3 mm, dehiscent by terminal pores that open into longitudinal slits; ovary glabrous. Berries dull green or purplish, globose, 0.5–0.8 cm diam., glabrous, with (4–)5–6(–13) sclerotic granules. Seeds tan, flat­tened, 1.2–1.5 × 1–1.1 mm, finely pitted. 2n = 24.

Flowering year-round. Deciduous and coniferous forests, fields, swampy areas; 0–1500 m; Ala., Fla., La., Miss., N.Mex., N.C., Tex.; Mexico; West Indies; Central America; South America.

Solanum nigrescens is widespread in Central and northern South America and the Caribbean and extends northward into the southeastern United States along the Gulf Coast and slightly inland. Where sympatric with S. americanum, it can be distinguished by its lon­ger anthers and dull green or purplish berries with appressed to spreading calyx lobes. Plants collected as weeds in rice and sugarcane fields of Louisiana and provisionally identified as the Chinese species S. merrillianum T. N. Liou are somewhat intermediate between S. americanum and S. nigrescens and could represent recent hybrid populations (S. Knapp et al. 2019). Solanum nigrescens differs from S. douglasii in its shorter anthers and longer filaments relative to anther length; moreover, S. douglasii is usually found west of the Rocky Mountains, whereas S. nigrescens occurs in the southeastern United States. The ranges of S. nigrescens and S. interius overlap (for example, in Texas). Solanum nigrescens may be distin­guished from S. interius by its usually acute calyx lobes, smaller seeds, and more numerous sclerotic granules in the fruits. Solanum nigrescens differs from S. nigrum in its more slender peduncles and pedicels, smaller seeds, and fruits with sclerotic granules.