Davis horsenettle

Herbs, annual, erect, moderately armed, 0.4–0.8 m, prickles whitish or yellowish, straight, needlelike, 3–15 mm, moder­ately to densely pubescent, hairs unbranched, glandular and eglandular, abaxial leaf surfaces also with sessile, few-rayed, stellate hairs, central ray equal to or longer than lateral rays. Leaves petiolate; petiole 2–6 cm; blade simple to compound, broadly ovate, 5–10 × 2.5–8 cm, margins 2–3 times lobed or divided with 3–4 main leaflets per side, leaflets with acute lobes, base truncate. Inflorescences extra-axillary, unbranched, 5–9-flowered, 4–7 cm. Pedicels 1–1.5 cm in flower, 1–1.5 cm and erect in fruit. Flowers bilaterally symmetric; calyx accrescent and tightly covering fruit, densely prickly, 3–5 mm, densely pubescent, lobes linear; corolla violet or blue, pentagonal-stellate, 1.4–2 cm diam., with interpetalar tissue at the margins and bases of lobes; stamens unequal, lowermost much longer and curved; anthers narrow and tapered, dehiscent by terminal pores, short anthers yellow, 4–5.5 mm, longer anther purplish, 5.5–8.5 mm; ovary glabrous. Berries brown, globose, 0.8–1 cm diam., glabrous, dry, without sclerotic granules. Seeds dark brown, flattened, 2.6–3 × 2–2.5 mm, minutely pitted. 2n = 24.

Flowering Jun–Sep. Igneous soils, sand or gravel streambeds; 900–2100 m; Tex.; Mexico (Coahuila).

In Texas, Solanum davisense is known only from the Chinati, Chisos, and Davis mountains.