Solanum nigrum L.
black nightshade
Unarmed, annual or short-lived perennial herb to c. 75 cm tall, usually hairy, sometimes nearly glabrous; stems branched, usually green, sometimes dark purple. Petioles to 7 cm long. Lamina c. 2-12 × 1-7 cm, ovate or lanceolate-ovate, entire, sinuate to coarsely dentate, sometimes lobulate, sometimes purple-tinged; hairs usually scattered, short, simple, occasionally glandular; base cuneate to narrowly attenuate; apex acute or obtuse. Cymes pseudoumbellate, usually few-flowered and with at least 1 pedicel arising below peduncle apex; peduncles generally 1-2.5 cm long; pedicels becoming deflexed at fruiting. Calyx 1-3 mm long; lobes ovate, broad-ovate, to almost elliptic, accrescent and appressed to fr. Corolla 10-13 mm diam., usually white, sometimes pale mauve; lobes almost triangular, ± puberulent outside. Anthers 2-2.7 mm long. Berry 7-10 mm diam., globose, usually black and rather dull, sometimes green, yellowish green or pale yellow; stone cells usually 0. Seeds 1.7-2.4 mm diam., broad-obovoid, ellipsoid-obovoid to suborbicular.
N.; S.: throughout; K. (Raoul and S. Kermadecs), Ch., C.
Eurasia 1853
Generally abundant, especially in open places such as arable land, waste places, dry riverbeds and roadsides, particularly much-disturbed areas.
FL Oct-May-(Sep).
S. nigrum is a very variable taxon and has been divided into a number of subspp. and vars. In N.Z. there is great variation in habit, hairiness, corolla size and colour, and fr. colour. The last character formed the basis for the records of var. chlorocarpum and var. humile (Healy, A. J., Proc. N.Z. Weed and Pest Contr. Conf. 27: 54 (1974)). These pale-coloured forms are occasionally found amongst populations of black-fruited plants ( var. nigrum) and are usually indistinguishable from them by any other character. Thus, they do not warrant varietal status, but may be treated as f. chlorocarpum (Spenner) Lindman (ripe frs green) and f. humile (Willd.) Lindman (ripe frs yellowish green or pale yellow and the plants tending to be semi-prostrate). Such green- and yellow-fruited plants have no stone cells. The somewhat similar Australian green berry nightshade, S. opacum (Symon, loc. cit.), should not be confused with these green and yellow forms of S. nigrum. O. opacum is usually prostrate or semi-prostrate, the cymes are 2-4-flowered, the berries have stone cells and it does not occur in N.Z.
S. nigrum appears to have replaced in N.Z., to some extent at least, S. americanum, which was the only black nightshade here in the second half of the 18th century.
S. nigrum may be poisonous (Connor 1977), although probably this only applies to green parts, including unripe frs. It should not be confused with, or referred to as, the much more toxic deadly nightshade, Atropa bella-donna.
