12. Solanum triflorum Nutt. (cutleaf nightshade)

Pl. 568 i, j; Map 2647

Plants annuals, taprooted (not producing tubers). Stems 10–40(–60) cm long, prostrate or spreading with loosely ascending tips, glabrous or sparsely pubescent with short, curved to appressed or less commonly spreading, few- to several-celled, nonglandular hairs (more densely so toward the tips); unarmed. Leaves unarmed, short- to long-petiolate, the petiole often narrowly winged, at least above the midpoint. Leaf blades 1–5 cm long, simple but deeply pinnately several-lobed with rounded sinuses, oblong to ovate in outline, angled or tapered to a sharply pointed tip, short-tapered to broadly angled at the base, the lobes broadly attached, lanceolate to nearly linear, the margins otherwise entire or with a few coarse, blunt teeth, usually rolled under, the surfaces glabrous or more commonly sparsely to moderately pubescent with short, appressed, 1- or few-celled, nonglandular hairs (sometimes mostly along the veins). Inflorescences axillary, of solitary flowers or umbels of 2 or 3 flowers, the flower stalks not jointed (but the fruits usually dispersed with the stalks attached), slender to somewhat stout, sometimes slightly thickened toward the tips. Flowers spreading to more or less pendant. Calyces 1.5–2.5 mm long at flowering, becoming enlarged to 4–6 mm at fruit, more or less cupped around the basal 1/3 of the fruit, 5-lobed (sometimes slightly unequally so) to below the midpoint, the lobes oblong-lanceolate to narrowly triangular, the outer surface sparsely to moderately pubescent (mostly toward the base) with short, relatively stout, nonglandular hairs. Corollas 4–7 mm long, white, sometimes pale purplish-tinged, yellow to yellowish green in the throat, lobed to at or below the midpoint, the lobes broadly lanceolate to bluntly triangular, spreading to somewhat recurved at full flowering, the inner surface glabrous, the outer surface minutely nonglandular-hairy, especially toward the tip. Anthers 2.0–2.5 mm long, oblong, lacking a sterile tip, dehiscing by terminal pores. Ovary 2-locular, the surface glabrous, the style usually exserted from the anther ring. Fruits 0.9–1.2 cm long, globose, with usually 4–15 stony granules, the surface glabrous, purplish black at full maturity but often remaining green for a relatively long time, then dull or shiny, often with lighter mottling or streaks. Seeds 2.0–2.5 mm in longest dimension, broadly obovate to nearly circular in outline, often minutely notched at the attachment point, strongly flattened, unwinged, the surface minutely pitted or with a very fine network of ridges, yellow. 2n=24. June–August.

Introduced, uncommon, sporadic (native of the western U.S. east to Minnesota and Oklahoma; Canada; introduced farther east). Railroads and open to semi-shaded, disturbed areas.

This species is generally described as having a foetid odor (Gleason and Cronquist, 1991).