Water spinach (Ipomoea aquatica) has been considered
native to Africa, Asia, and the southwestern Pacific
Islands. The herbs have been a medicinal vegetable in
southern Asia since at least A.D. 300, and perhaps since
200 B.C. People still gather plants from the wild and cultivate
them. With European arrival in these regions in the
late 1400s, they became aware of this medicinal food and
began carrying water spinach around the world. As with
other transported plants, Europeans took along some
common names and cultural uses. With the later migration
of people from Asian countries to other parts of the world,
the food was imported into new areas. Doubt persists as
to where the species was domesticated. Data from uses
as food, regions of cultivation, medicinal use, phylogenetic
studies, common names, and pathogens suggest that
water spinach was first cultivated in southeastern Asia.
The plants may have been domesticated in China and India,
but the data are equivocal. The vegetable sometimes
escapes from cultivation to become an ecologically invasive
weed