Solanum nigrum is an annual herb to 60 cm tall, usually lower, branching, sprawling. Plants may be toxic, fresh whole plants contain 2.7g/kg solanine, fresh stems contain 570 g/kg nitrate (Bassett and Munro 1985).
Leaves alternate, irregularly toothed, more or less egg-shaped, to 8 cm long, 5 cm wide, tip pointed, base often truncate..
Flowers white, radially symmetrical, small, about 0.7 cm wide, star-shaped, with central column of yellow stamens; inflorescence of small, umbrella-shaped clusters, mostly self-pollinated blooms June-Oct Hough 1983).
Fruit fleshy, black, rounded, to 1.2 cm, unripe fruit poisonous, containing toxic, distasteful glycoalkaloids that deter fungal infection, but do not prevent dispersal by birds and some mammals (Cipollini and Levey 1997a). Fresh, mature fruit contains 28g/kg solanine (Bassett and Munro 1985); less than 0.2% glycoalkaloids in dry weight ripe fruit pulp (Cipollini and Levey 1997b). Seeds 15-60, 0.2 cm, whitish. Seed is 73% viable in soil after six years but drops to 2% after about 9 yr. Europe (apparently worldwide distribution).
Wetland status: FACU-.
Frequency in NYC: Frequent.
Habitat: Part shade of edges, low vegetation, disturbed areas, roadsides, weedy habitats. Full sun is necessary for maximum flowering.
Notes: Black nightshades have been used as medicinals in many countries. Chemicals extracted from black nightshade include; diosgenin (a steroid) and salasodine, (a steroidal alkaloid), have been used in the production of various pharmaceuticals (Bassett and Munro 1985). Black nightshade is eaten by the tobacco and potato flea beetles (Epitrix hirtipennis, E. cucumeris; Coleoptera) and the spinach leaf miner (Pegomya hyoscyami; Diptera). It is also host to a number of fungi including; Alternaria consortialis (Deuteromycotina, Hyphomycetes), a genus often colonizing leaf surfaces, Eryiphe cichoracearum (Erysiphales) a genus causing powdery mildews, and Phytophthora infestans (Oomycetyes, Perenosporales, Pythiaceae) the infamous causal agent of the Irish potato famine. The name Phytophthora means “plant destroyer” (Bassett and Munro 1985; Sinclair et al. 1987). Many species in this genus of fungi cause plant diseases. Fungi isolated from ripe fruit include: Saccharomyces sp. (Ascomycotina, Endomycetales, a yeast); Botrytis cinerea (Deuteromycotina, Hyphomycetes) blossom blights, fruit rot, diseases of numerous plants, later stages appearing as a gray mold; Rhizopus stolonifer (Zygomycotina, bread molds) causing soft rots of fruits (Agrios 1988; Cipollini and Levey 1997b). Solanum nigrum.commons.wikipedia.org. (Accessed 4/2014).