Out of 72 genera of the family Solanaceae, only eight genera namely Atropa, Hysocyamus, Scopolia, Mandrogora, Physochlaina, Datura, Solandra and Duboisia contain atropine, hyoscyamine and hysocine. The species under these genera can be classified into three categories:

Table 3.4 Important plant sources of tropane alkaloids

L leaves, FT flowering tops, R root, S stem, Sd seeds.

1. Those containing hysocyamine or atropine as the major alkaloid are Atropa belladonna, A. acuminata, A. boetica, Datura stramonium, D. metel, D. quercifolia, Duboisia leichhardtii, Hysocyamus muticus, Scopolia carniolica, S.anomala, Solandra laevis, Physochlaina praealta;
2. Those containing hyoscine as the major alkaloid are D. innoxia, D. metel, Duboisia myoporoides;
3. Those species containing both hyoscine and hysocyamine, but in low concentration are Hyoscyamus niger, H. reticulatus, H. albus, Mandrogora officinarum.