Plants annnual or perennial herbs, shrubs, trees or vines, often growing from starchy underground tubers. Stems and young branches with or without prickles, often with glandular, simple or stellate hairs. Leaves alternate or paired and frequently unequal in size, simple tp pinnately lobed or compound, without stipules, petiolate or sessile. Inflorescences basically cymose, unbranched or branched and appearing racemose, umbellate, or paniculate, terminal, axillary, extra-axillary, or leaf opposed, usually all flowers bisexual but sometimes basal flowers bisexular or pistallate and distal flowers staminate. Flowers 5-merous, radially to slightly bilaterally symmetric; calyces campanulate,rotte or cup-shaped,with acute or acuminate lobes, sometimes enlarged in fruit; corollas deeply lobed, the lobed folded in bud, in flower usually rotate, campanulate, stellate or urceolate, blue, purple, yellow, green or white ; stamens usually equal but sometimes one stamen different from the rest, usually inserted in the throat of the corollas; filaments usually short; anthers basifixed, often coherent around the style, opening by terminal pores, pores sometimes elongating into slits with age; ovaries superior, 2-celled, with many ovules; styles articulate at base, usually slender, simple; stigmas capitate or bified. Fruits berries, usually fleshy but sometimes dry and papery, or leathery, sometimes included in the accrescent fruiting calyx; seeds flattened, white, brown or black.
Solanum includes about 1500 species. Its greatest diversity is in South America, particularly in the Andes but secondary centers of diversity and endemism occur in North America and Mexico, eastern Brazil, the West Indieas, Australia, Africa, and Madagascar. The above description includes Lycopersicon, as recommended by the Solanaceae Source (http://solanaceaesource.org/content/solanum-genus-solanaceae)