Opening/ Closure Status

All outdoor gardens are currently open. The Conservatory and public restrooms remain closed, due to the closure of the U.S. Capitol campus buildings. Please monitor for updates on operating status. USBG resources can be accessed online, including educational materials, virtual tours, and online programs by visiting

Koa'oha or Koai‘a

Koai‘a or Acacia koaia
Plant Botanical Name: 
Acacia koaia
USBG Plant Location: 
Conservatory Room Location: 
Plant Threat Level: 

The Koa' oha tree is native to Hawaii and can be found on the islands of Kaua'i, O'ahu, Moloka'i, Lana'i, and Maui in dry, lowland habitats. Native Hawaiians used the tree's leaves to make a tea for medical baths, bark to dye cloth and wood for surfboards, paddles, and ukuleles. The dry, lowlands areas that the koaoha favors is also prime location ranching and agriculture. Due to increased agricultural activity, the koa' oha's habitat has decreased substantially as it is additionally threatened by grazing livestock and encroachment of non-native species giving it a "G2" ranking by NatureServe, "Vulnerable" by IUCN, and as a "Species of Concern" by the United States.