5. Solanum americanum Miller, Gard. Dict., ed. 8. no. 5. 1768.
少花龙葵 shao hua long kui
Solanum ganchouenense H. Léveille; S. nigrum Linnaeus var. pauciflorum Liou; S. photeinocarpum Nakamura & Odashima.
Herbs annual or short-lived perennial, glabrescent or puberulent with simple hairs. Stems green or purple, mostly erect, 25-100 cm tall. Petiole 1-2 cm; leaf blade ovate, 4-8 × 2-4 cm, membranous, glabrescent or sparsely pubescent, base truncate to cuneate, margin entire or sparingly dentate, apex acute. Inflorescences extra-axillary, subumbellate, 3-6(-l0)-flowered; peduncle 1-2.5 cm. Pedicel 5-10 mm. Calyx cup-shaped, 1.5-2 mm in diam., lobed nearly halfway; lobes ovate, pubescent abaxially, ciliate. Corolla white, rarely bluish or purplish, sometimes with a yellow eye, 3-5 mm, lobed halfway or more; lobes ovate-oblong, 3-4 mm, pubescent abaxially, ciliate. Filaments short, ca. 0.5 mm, puberulent; anthers 1-1.5 mm. Fruiting pedicel erect or nodding; fruiting calyx strongly reflexed. Berry shiny black, occasionally ripening green, globose, 5-8 mm in diam. Seeds discoid, 1.5-2 mm in diam. Fl. Jun-Oct, Fr. Jul-Jan.
Waste places, roadsides, fields; 100-2000 m. Fujian, Guangdong, Guangxi, Hainan, Hunan, Jiangxi, Sichuan, Taiwan, Yunnan [widespread in all tropical and temperate regions]
The leaves are used as a vegetable, yielding a heat-clearing effect. Whole plant can be used for treating inflammation, dissipating blood stasis, and promoting the subsidence of swelling, also clearing away heat and detoxifying.
This species was reported in FRPS as Solanum nigrum and S. photeinocarpum. However, S. nigrum is actually a different species, treated below. A variant of S. americanum was
reported for China by Wessely (Feddes Repert. 63: 293. 1960) as S. nigrum L. var. violaceum Chen and in FRPS as S. photeinocarpum var. violaceum (Chen) C. Y. Wu & S. C. Huang,
but we were unable to locate the original description of this variety or material of it.
Solanum ganchouenense was based on a specimen from Guizhou, which was not seen for this treatment. The original description separates the species from S. nigrum in having
narrower leaves, larger umbellate inflorescences with more flowers, and revolute anthers that dry green. The anther description more resembles Capsicum than Solanum.
Some material of this species was recorded in FRPS as Solanum suffruticosum Schousboe. The type of the latter (B-W 4363), with its slender, slightly elongated inflorescences and
sparingly dentate leaves, resembles S. americanum, but from the microfiche copy available, this determination is not certain.
Solanum opacum A. Braun & Bouché, which resembles S. americanum except for its yellowish green fruit, may also occur in Yunnan.