Vigna owahuensis

Vigna owahuensis
Conservation status
Critically Imperiled  (NatureServe)
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Fabales
Family:	Fabaceae
Subfamily:	Faboideae
Tribe:	Phaseoleae
Genus:	Vigna
Species:	V. o-wahuensis
Binomial name
Vigna o-wahuensis Vogel
Synonyms
Vigna sandwicensis

Vigna o-wahuensis is a rare species of flowering plant in the legume family known by the common name Oahu cowpea. It is endemic to Hawaii, where it is known from seven small populations on the islands of Hawaii, Molokai, Lanai, and Kahoolawe. Though it was described from a specimen collected on Oahu it is now extirpated from that island. It was also known from Niihau, Maui, and Kauai in the past. It is threatened by habitat destruction and degradation. It is a federally listed endangered species of the United States.

This is an annual or perennial herb growing up to 40 centimeters long. Each leaf has three hairy leaflets of widely varying shape and size. Flowers occur singly or in clusters of up to four. They are light yellow or greenish in color and are about 2 or 2.5 centimeters long. The fruit is a long, thin legume pod up to 9 centimeters in length. The pod may be slightly inflated or not. It contains up to 15 gray or black beans around half a centimeter long.

There are fewer than 100 individuals in total remaining on four islands. Two of the seven populations are on Molokai, one occurring in a plantation of tropical ash and pine trees. As of the year 1994 there was only one plant known on Lanai. There are several individuals on Hawaii and Kahoolawe.

This plant grows in many types of shrubland and grassland habitat, as well as in some cultivated areas. It occurs on cinder cones and offshore islets and exposed coral reefs.

The species faces many threats, including loss of habitat to agriculture and development, degradation of the habitat by exotic plants and animals, and military activity.

External links

• USDA Plants Profile