The sweet pea, Lathyrus odoratus, is a flowering plant in the genus Lathyrus in the family Fabaceae (legumes), native to Sicily, southern Italy and the Aegean Islands.

Lathyrus is a genus of flowering plants in the legume family Fabaceae, and contains approximately 160 species. Commonly known as peavines or vetchlings, they are native to temperate areas, with a breakdown of 52 species in Europe, 30 species in North America, 78 in Asia, 24 in tropical East Africa, and 24 in temperate South America. There are annual and perennial species which may be climbing or bushy. This genus has numerous sections, including Orobus, which was once a separate genus. The genus has numerous synonyms, including Pisum, the ancient Latin name for the pea.