Hoe or hairy nightshade

Solanum physalifolium Rusby var. nitidibaccatum (Bitter) Edmonds

Herbs, annual, erect or pros­trate, unarmed, to 0.2(–0.4) m, moderately to densely pubes­cent, hairs unbranched, 1.5–2 mm, glandular. Leaves petio­late; petiole 0.5–3 cm; blade simple, ovate to lanceolate, 2–10 × 1–5 cm, margins entire to sinuate-dentate, base cuneate to decurrent. Inflorescences usually extra-axillary, occasionally leaf-opposed, unbranched, 4–8(–10)-flowered, 1–2 cm. Pedicels spreading to reflexed and 0.4–1 cm in flower and fruit. Flowers radially symmetric; calyx accrescent and covering ca. one-half berry, unarmed, 3–4 mm, sparsely to moderately pubescent, lobes broadly triangular; corolla white with yellowish central star edged with reddish purple to dark brown, rotate-stellate, 0.5–1 cm diam., with sparse interpetalar tissue; stamens equal; anthers ellipsoidal, 1–1.4 mm, dehiscent by terminal pores that open into longitudinal slits; ovary glabrous. Berries shiny greenish to purplish brown, globose, 0.5–1 cm diam., glabrous, with (0–)2–3 sclerotic granules. Seeds yellow to brown, flattened, 1.5–2.5 × 1.5–2 mm, minutely pitted. 2n = 24.

Flowering May–Oct. Disturbed areas, fields; (0–)1200–2500 m; B.C., Man., N.B., Ont., Que.; Alaska, Ariz., Ark., Calif., Colo., Idaho, Mass., Minn., Mo., Mont., Nev., N.Mex., N.Y., N.C., N.Dak., Oreg., Pa., Tex., Utah, Wash., Wis., Wyo.; South America (Argentina, Chile); introduced in Europe, Africa, Pacific Islands (New Zealand), Australia.

Solanum nitidibaccatum has often been confused with and misidentified as S. sarrachoides, which has a much longer fruiting calyx that nearly covers the mature berry. Solanum nitidibaccatum also differs from S. sarrachoides in its smaller leaves, larger number of flowers per inflorescence (four to eight versus three or four in S. sarrachoides), and fruits with usually two or three sclerotic granules (versus four to six in S. sarrachoides).

Most references to Solanum sarrachoides in North American floras are actually S. nitidibaccatum. Solanum nitidibaccatum has also been confused with S. villosum Miller (R. L. McGregor 1986). J. M. Edmonds (1986) regarded S. nitidibaccatum as a variety of S. physalifolium, but the two taxa are now recognized as distinct species, with S. physalifolium restricted to South America. The name S. physalifolium, however, has been used for S. nitidibaccatum in a number of North American floras.

Solanum nitidibaccatum is currently considered to be native to both North and South America. It is a common weed in cultivated fields in the Great Plains, Pacific Northwest, and adjacent parts of Canada.

SELECTED REFERENCE Edmonds, J. M. 1986. Biosystematics of Solanum sarrachoides Sendtner and S. physalifolium Rusby (S. nitidibaccatum Bitter). Bot. J. Linn. Soc. 92: 1–38.