|Listed||August 21, 1985|
|Description||A small tropical tree.|
|Habitat||Dry scrub and forest on well-drainedsites.|
|Threats||Habitat destruction, introduced mammalian herbivores, invasive non-native plants, wildfire.|
The Hawaiian gardenia, or na'u, is a small tree up to 20 ft (6 m) tall, with a trunk diameter of up to 12 in (30 cm). It has beautiful, white, fragrant flowers.
The na'u occurs in dry scrub and forest on sites with well-drained, lateritic, nutrient-poor soils. It occurs at altitudes from 1,000 to 1,800 ft (300-550 m).
The na'u is a local (or endemic) species that is only known from the islands of Hawaii, Maui, Moloka'i, O'ahu, and Lana'i. The Hawaiian archipelago has an extremely large fraction of endemic species; about 89% of the indigenous flowering plants occur nowhere else in the world.
The na'u has declined greatly in range and abundance. Most of its original habitat has been lost through conversion into agricultural, commercial, and residential land uses. Its tiny surviving populations are severely threatened by alien plant competitors, introduced mammalian herbivores, fire, and pathogens. Only six populations are known to survive, totaling about 15 to 19 individual trees, all growing on private property. It is extirpated from the islands of Maui and Hawaii.
Conservation and Recovery
The State of Hawaii has funded efforts by the Hawaii Plant Conservation Center to propagate the na'u from seed. This has resulted in the cultivation of plants originating from seeds from O'ahu sites and from a Lana'i population (Kanepu'u). The private landowner of the island of Lana'i has provided funding to fence three endangered trees of the na'u at Kanepu'u on land that is managed by the Nature Conservancy of Hawaii as the Kanepu'u Preserve. Starting in the 1970s, volunteers and environmental organizations, including the Hui Malama Pono o Lana'i, erected protective fences around the Kanepu'u individuals of the na'u. Some private individuals are known to have a few endangered na'u in their gardens. It is possible that these private gardens contain wild-collected genotypes not represented in the botanical gardens. Apart from these actions, it is essential that the remaining habitat of the na'u be effectively conserved. The privately owned land should be set aside as protected areas, either by acquisition or through the negotiation of conservation easements. Greater efforts should be made to out-plant trees grown from seed in captivity, and the habitat should be managed to reduce the impacts of introduced herbivores, alien plants, and other threats to the endangered na'u.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
U. S. Fish and Wildlife Service, Pacific Islands
300 Ala Moana Boulevard, Room 3-122
P.O. Box 50088
Honolulu, Hawaii 96850
Telephone: (808) 541-2749
Fax: (808) 541-2756
U. S. Fish and Wildlife Service. March 2000. "U.S. Fish and Wildlife Service Threatened and Endangered Species: The Recovery Plan for Hawaiian Gardenia." U. S. Fish and Wildlife Service Pacific Islands Ecoregion. (http://www.r1.fws.gov/pacific/wesa/higardeniaindex.html). Date Accessed: July 6, 2000.