'Oha Wai

Clermontia pyrularia

Description

This 'oha wai, Clermontia pyrularia, is a terrestrial tree 10-13 ft (3-4 m) tall, has alternate, toothed leaves 5.9-11 in (15-28 cm) long and 1-2 in (2.5-5.1 cm) wide, with winged petioles. A cluster of up to five flowers has a main stalk 1.1-2.4 in (2.8-6.1 cm) long; each flower has a stalk 0.3-0.8 in (0.8-2 cm) long. Five small green calyx lobes top the hypanthium. The white or greenish white petals are covered with fine hairs, measure 1.6-1.8 in (4-4.6 cm) long, and are fused into a curved two-lipped tube 0.2-0.3 in (0.5-0.8 cm) wide with five spreading lobes. The orange berry is inversely ovoid or pear-shaped. This species is distinguished from others of the genus by its winged petioles; its small, green calyx lobes; its two-lipped flowers with white or greenish white petals; and the shape of the berry. This species was observed in fruit and flower during December 1978 and November 1957. No other life history information is currently available.

Habitat

This species typically grows in koa and/or 'ohi'a dominated montane wet forests and subalpine dry forests at elevations between 3,000 and 7,000 ft (914 and 2,134 m). Associated species include pilo (Platydesma sp.), pukamole (Lythrum mariturnum ), and 'akala.

Distribution

Historically, 'oha wai has been found only on the island of Hawaii on the northeastern slope of Mauna Kea, the western slope of Mauna Loa, and the saddle area between the two mountains.

Since 1975, two populations have been identified on state and federal lands in north Hilo at elevations of 5,900-6,240 ft (1,798-1,901 m). One population consisted of an individual previously found near Laupahoehoe Natural Area Reserve; the plant is now dead and this population may be extirpated. The second population consists of three plants found on state land at Piha, adjacent to the Hakalau National Wildlife Refuge (NWR). Although this second population also originally consisted of one plant that eventually died, three more plants were recently discovered. In addition, approximately 30 individuals grown from seeds of the original plant were outplanted in two enclosures at Hakalau NWR by refuge staff in December 1990 and June and July 1992.

Threats

Alien grasses, shrubs, and vines, particularly banana poka (Passiflora mollissima ), negatively impact C. pyrularia. The canopy of banana poka is shading out seedlings in Piha and must be controlled. By rooting and trampling native vegetation and eliminating juveniles, pigs also appear to be a major contributor to the taxon's demise. Pigs are attracted by the fruits of Passiflora mollissima and the fruits are dispersed in their digestive tracts, hooves, and hair.

Predation on fruits and seeds of C. pyrularia by black rats may limit the successful establishment of new plants. Scattered distribution, few populations, and small number of individuals make this taxon highly vulnerable to random events and human impacts, and may also affect reproductive vigor. The plant originally known from Piha rapidly died from unknown causes in 1995. There was no indication of natural reproduction even though viable seeds for the outplants were produced. The general decline of the environment may have eliminated or reduced native vectors and thereby precluded or lessened pollination. Other individuals known from the Piha area disappeared a few years ago, probably eaten by cattle. The area is pasture land and is heavily grazed.

Conservation and Recovery

Volcano Rare Plant Facility at the Volcano Agricultural Station has successfully germinated C. pyrularia and currently has approximately 50 seedlings growing in the greenhouse. Lyon Arboretum has successfully cloned the taxon and has about 100 seedlings in the greenhouse.

Approximately 30 individuals have been out-planted and are growing in two enclosures at Hakalau NWR. Seeds were acquired from the wild plant at Piha that died in 1989. The individuals grown from seed are healthy and two or three have flowered. There are plans to fence the three remaining wild plants in the near future.

The known remaining individuals should be protected from ungulates and encroachment of alien plants. In order to prevent possible extinction of this taxon, maintenance of ex situ genetic stock is necessary. Propagation and outplanting of ex situ stock will be needed in order to establish a sufficient number of populations and plants for recovery. Research into the taxon's pollination vectors may be necessary.

Contacts

Pacific Joint Venture
300 Ala Moana Blvd., Rm. 3-122
Honolulu, Hawaii 96850-0056
Phone: (808) 541-2749
Fax: (808) 541-2756

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

Reference

U.S. Fish and Wildlife Service. 4 March 1994. "Endangered and Threatened Wildlife and Plant; Determination of Endangered or Threatened Status for 21 Plants from the Island of Hawaii, State of Hawaii." Federal Register 59 (43): 10305-10325.