Kava kava or Kava (Piper methysticum) is a plant from the pepper family (Piperaceae) that was domesticated for its ability to produce compounds called kavalactones. These compounds are found in the roots of Kava and are extracted to produce a drink with sedative, anesthetic and sometimes even hallucinogenic properties.  This drink is used throughout the Pacific for cultural, political and social activities and is popular in the Polynesian cultures of Fiji, Vanuatu, and Hawaii. Although there are many different kavalactones are found in trace amounts in individual Kava kava plants, the relative ratio and abundance of six kavalactones in a plant make up a unique chemotype that dictates the effects of a particular kava kava beverage. These chemotypes frequently differ between islands and are most diverse on the islands of Vanuatu. This is one line of evidence that domestication of Kava occurred on Vanuatu from the close relative P. wickmannii. However, sexual reproduction has rarely been observed in cultivars of Kava, and agricultural and evolutionary studies of Kava are far from conclusive.

--Nic Kooyers

For more information see :

Kava: The Pacific Elixir: The Definitive Guide to Its Ethnobotany, History, and Chemistry

by Vincent Lebot, Mark Merlin and Lamont Lindstrom