Phyllostegia wawrana

No Common Name

Description

Phyllostegia wawrana, a perennial vine in the mint family, is woody toward the base and has long, crinkly hairs along the stem. The leaves are opposite, ovate, and covered with hairs, especially along the veins of the lower surface. The leaves are 4.1-7.8 in (10-20 cm) long and 1.6-4.3 in (4-11 cm) wide. Flowers are borne in groups of four to six along a leafy flower stalk with one or two short lateral branches. Each of these lateral branches have a pair of leaves at the base. The corolla tube is about 0.03 in (0.7 mm) long, with an upper lip about 0.08 in (2 mm) long. The fruits are four greenish-black nutlets in each flower and are about 0.8 in (2 cm) long. This species may be related to P. floribunda and P. knudsenii, but has a less specialized flower stalk. Seeds were observed in 1993.

Habitat

P. wawrana grows in 'ohi'a-dominated forest with either 'olapa or uluhe as codominant species. Associated species include Diplazium sandwichianum, 'ohelo, kanawao, kolea, kopiko, Dubautia knudsenii (na'ena'e), Scaevola procera (naupaka kuahiwi), Gunnera sp., Pleomele aurea (hala pepe), Claoxylon sandwicense (po'ola), Elaphoglossum sp., 'ala 'ala wai nui, manono, hapu'u, 'ama'u, ho'awa, 'uki, and Syzygium sandwicensis ('ohi'a ha).

Distribution

P. wawrana, reported from Hanalei in the 1800s and last observed along Kokee Stream in 1926, was rediscovered in 1993, when National Tropical Botanical Garden botanists found two populations on state-owned land. There are now a total of 20-30 individuals in the Makaleha Mountains and five or six in Honopu Valley.

Threats

The major threats to P. wawrana include degradation of habitat by feral pigs and competition with alien plant species such as thimbleberry, banana poka, prickly Florida blackberry, Melastoma candidum, fireweed, and daisy fleabane. All known populations of P. wawrana are threatened by feral pigs. Fireweed, an annual herb native from Mexico to Brazil and Argentina; Melastoma candidum, a noxious weed; and thimbleberry threaten the Makaleha Mountains population, while daisy fleabane, prickly Florida blackberry, and banana poka threaten the Honopu Valley population.

Conservation and Recovery

P. wawrana has been successfully propagated from seed, and one plant is in cultivation at National Tropical Botanical Garden.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Building
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
http://pacific.fws.gov/

Reference

U. S. Fish and Wildlife Service. 10 October 1996. "Endangered and Threatened Wildlife and Plants; Determination of Endangered or Threatened Status for Nineteen Plant Species From the Island of Kauai, Hawaii." Federal Register 61(198):53070-53089.