Gouania is a genus of between 50-70 species of flowering plants in the family Rhamnaceae, native to tropical and subtropical regions of the world, including Africa, Madagascar, the Indian Ocean islands, southern Asia, the Americas and Hawaii. They are shrubs or lianas.Selected species

• Gouania corylifolia – Brazil
• Gouania hillebrandii – Hawaii
• Gouania leptostachya – southern Asia (India east to the Philippines)
• Gouania longispicata – Africa (Nigeria east to Sudan and south to Zimbabwe)
• Gouania lupuloides (Chewstick or Toothbrush Tree) – Central and northern South America
• Gouania meyenii – Hawaii
• Gouania napalensis – India, Nepal
• Gouania polygama – Mexico south to Argentina
• Gouania vitifolia – Hawaii

A revision of the species in Madagascar and the other western Indian Ocean islands is in preparation, where the genus has an important centre of diversity. The work will recognise several new species.

References

• Germplasm Resources Information Network: Gouania
• Madagascar Catalogue: Gouania
• Flora of Zimbabwe: Gouania