Torrey’s nightshade, western or robust horsenettle

Solanum torreyi A. Gray

Herbs, perennial, erect, sparsely to moderately armed, to 1 m, prickles cream to yellowish, straight or slightly curved, to 6.5 mm, sparsely to densely pubescent, hairs whitish, ses­sile to short-stalked, stellate, (4–)6–10-rayed, central ray 1-celled and equal to or shorter than lateral rays. Leaves petio­late; petiole 1–4 cm; blade simple, ovate, 6–15 × 3–10 cm, margins sinuate or shallowly to deeply lobed with 2–4 lobes per side, lobe margins entire to coarsely lobed, base truncate to cuneate and often oblique. Inflorescences extra-axillary, 1–several times branched, to ca. 20-flowered, 6–14 cm. Pedicels 1–2.5 cm in flower, 1.5–3 cm and curved downward in fruit. Flowers radially symmetric; calyx not accrescent, unarmed or with sparse prickles, 6–14 mm, densely stellate-pubescent, lobes ovate-lanceolate; corolla lavender, pale blue, or sometimes white, stellate to stellate-pentagonal or rotate-stellate, 2–4.6 cm diam., with abundant interpetalar tissue at margins and bases of lobes; stamens equal; anthers narrow and tapered, 5–9 mm, dehiscent by terminal pores; ovary minutely pubescent, hairs simple and stellate, rarely densely stellate-pubescent, glandular and eglandular. Berries yellow, subovoid to depressed-globose, 1–2 × 1–2.5 cm, glabrous, without sclerotic granules. Seeds yellow, flattened, 1.9–3 × 1.7–2.5 mm, minutely pitted. 2n = 72.

Flowering Apr–Oct. Prairies, woodlands, disturbed areas; 20–700(–2000) m; Ark., Calif., Ill., Kans., La., Mo., N.Mex., Okla., S.C., Tex.; Mexico (Nuevo León); introduced in Australia.

Solanum dimidiatum is found mainly in the south­central United States, with outlier populations in Illinois, Missouri, New Mexico, and South Carolina. The species is introduced in California, where it is con­sidered a noxious weed by the California Department of Agriculture.