Tomatoes (Solanum lycopersicum) are members of the Solanaceae or Nightshade family of plants.
This is a large worldwide family with over 90 genera and 2500 species containing not only tomatoes but many other of our most important food plants such as; Potatoes (Solanum tuberosum), Eggplants (Solanum melongena), Capsicums and Chillies (Capsicum spp.). With the exception of Eggplants these plants arrived from the New World in the sixteenth century and gradually transformed the cuisines and diets of much of the planet including Asia, Europe and parts of Africa.
The Nightshade family is also characterised by the number of its members that produce alkaloids, chemicals produced by plants that can have dramatic physiological effects on animals including humans.
Mandrake (Mandragora autumnalis) featured in the Harry Potter movies, Belladonna (Atropa belladonna) used by Venetian women to enhance their beauty and Tobacco (Nicotiana tabacum) are three examples of alkaloid producing plants some of which are now used in producing modern pharmaceuticals.