Solanum triquetrum Cav.

Semi-woody vine or scrambler with an enlarged woody base, to 2 m long, occasionally an erect subshrub to 0.5 m tall. Stems somewhat angled, glabrous to pubescent with weak simple uniseriate trichomes to 0.5 mm long, these usually ascending and pointing to the distal part of the stems; new growth sparsely to densely pubescent with simple uniseriate trichomes to 0.5 mm long, but usually shorter. Bark of older stems pale greenish yellow. Sympodial units plurifoliate. Leaves simple to basally lobed and hastate, (1.1-)1.8–5(+) cm long, (0.3-)1–3.5 cm wide, deltate to hastate, triangular in outline, sometimes linear, slightly fleshy, the upper and lower surfaces pubescent with simple uniseriate trichomes along the margins and on the veins to uniformly pubescent on the veins and lamina, the trichomes to 0.5 mm long, white; primary veins 3–5 pairs, only just visible in dried material, sometimes slightly impressed above; base abruptly truncate to hastate with 2 basal lobes to 1 cm long, these rounded at the tip; margins entire to basally lobed; apex acute to acuminate, the tip sometimes rounded; petioles 0.3–1.2 cm long, glabrous but with a line of simple trichomes adaxially, apparently only sometimes twining. Inflorescences terminal or lateral, 1–3 cm long, usually simple, very occasionally furcate, with 3–6 flowers, glabrous to pubescent like the stems, the pubescence like that of the rest of the plant; peduncle 0.3–1 cm long; pedicels 0.6–1.2 cm long, ca. 0.5 mm in diameter at the base, ca. 1 mm in diameter at the apex, slender, sometimes tinged purple, glabrous to sparsely pubescent with simple uniseriate white trichomes, articulated at the base from a short sleeve 0.5–1 mm deep; pedicel scars irregularly spaced 1–4 mm apart. Buds when young globose, later ellipsoid, the corolla strongly exserted from the calyx tube before anthesis. Flowers all perfect, usually 5-merous. Calyx tube 1–1.5 mm long, conical, the lobes 1.5–2 mm long, triangular with the tips often long-acuminate, often purplish tinged, glabrous to sparsely pubescent abaxially, densely papillate adaxially, pubescent with simple trichomes to 0.2 mm on internal surface of tips. Corolla 1.5–1.9 cm in diameter, white or tinged with purple, often with a shiny green or greenish white eye, stellate, lobed nearly to the base, the lobes 0.8–0.9 mm long, ca. 0.3 cm wide, reflexed at anthesis, the midvein often tinged purple, glabrous to sparsely pubescent abaxially especially along the distal margins and tips, glabrous adaxially. Filament tube minute, the free portion of the filaments ca. 1 mm long, glabrous; anthers 3.5–4 mm long, 1–1.5 mm wide, ellipsoid, loosely connivent, poricidal at the tips the pores lengthening to slits with age. Ovary glabrous; style 6–8 mm long, glabrous; stigma capitate to somewhat clavate, the surface minutely papillose. Fruit a globose to slightly ellipsoid berry, to 1.5 cm in diameter, bright red when ripe, the pericarp thin and shiny, glabrous; fruiting pedicels 1–1.5 cm, ca. 1 mm in diameter at the base, somewhat woody, deflexed or spreading. Seeds (2-)6–10 per berry, ca. 4 mm long, 2.5 mm wide, flattened to thickened reniform, reddish brown, the surfaces minutely pitted, in mature fruits the lateral testal cell walls exposed and the seed prominently silky, the testal cells rectangular to slightly sinuate. Chromosome number: not known.

(Figure 98). In the USA in central, south and west Texas and northern Mexico, south to the state of Coahuila, from sea level to 500 m elevation.

Solanum triquetrum, the Texas nightshade, is a species of flowering plant in the family Solanaceae, native to Texas and northeastern Mexico. A perennial, it is usually 1 to 2 ft (30 to 60 cm) tall, but if given a support to climb on it can reach 7 ft (2 m).

Solanum triquetrum là loài thực vật có hoa trong họ Cà. Loài này được Cav. miêu tả khoa học đầu tiên năm 1795.