Alani

Melicope mucronulata

Description

This alani (Melicope [=Pelea ] mucronulata ), a small tree in the rue family (Rutaceae) with oval to elliptic-oval leaves 3.2-6.3 in (8.1-16 cm) long, can reach a height of 13 ft (4 m). The flower clusters, composed of three to nine flowers, are arranged in the leaf axils. The fruit, about 1 in (2.5 cm) wide, is made of separate sections, each containing one to two seeds. This species is distinguished from others in the genus by the growth habit, the number of flowers in each flower cluster, the size and shape of the fruit, and the degree of hairiness of the leaves and fruit walls.

Habitat

M. mucronulata typically grows on steep, west-or north-facing, dry to mesic forested lowland slopes at elevations of 2,200-2,850 ft (671-869 m). Associated plants species include 'a'ali'i, 'ohi'a pukiawe, and na'ena'e.

Distribution

M. mucronulata, first discovered in 1920, was known historically from only three collections made at Kanaio on East Maui; then, in 1985, it was found in the Kamakou Preserve on East Molokai. The two populations, which together extend over an area of 950 acres (385 hectares), contain a total of only three to five plants.

Threats

The primary threats historically responsible for the endangerment of this species include habitat degradation by goats, cattle, and pigs and competition with alien plants. The three remaining individuals of M. mucronulata on Molokai have been browsed by goats. Although the plants appeared vigorous when last seen in 1994, continued predation would severely threaten the population. This population is also threatened by molasses grass and seed predation by native insects. The endemic microlepidopteran (a type of moth) is known to feed on the buds, flowers, and seeds of Melicope and Platydesma.

The very small remaining number of individuals of M. mucronulata and their limited distribution are major threats to the continued existence of this species; a single natural or human-caused environmental disturbance could easily cause its extinction. The limited gene pool may also depress reproductive vigor.

Conservation and Recovery

M. mucronulata has been successfully propagated at the National Tropical Botanical Garden, while the Lyon Arboretum on Oahu has attempted to propagate the species.

The feral goats and invasive alien plants that presently threaten the handful of remaining individuals need to be controlled immediately through ungulate removal, fencing, and weed control.

It is important to determine whether the three known individuals on Molokai are taxonomically identical to the plants on Maui so that emergency plans can be carried out to obtain plant material from Molokai for reintroduction onto Maui, if necessary. Potential sites for relocation on East Maui include Kanaio State Natural Area Reserve, Ulupalakua Ranch, and the Kaupo Gap area of Haleakala National Park.

Another emergency measure is to establish suitable habitat with quicker growing native species that will mimic the conditions of pristine dryland-forest understory. The increased humidity, soil moisture, and shade and the decreased wind exposure may increase survival of out-planted germinants of this species. This emergency experimental effort could be conducted either on Molokai or on East Maui in conjunction with similar efforts for other highly depleted dryland-forest species.

Contacts

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
http://pacific.fws.gov/

Pacific Remote Islands Ecological Services Field
Office
300 Ala Moana Blvd., Room 3-122
P.O. Box 50088
Honolulu, Hawaii 96850
Telephone: (808) 541-1201
Fax: (808) 541-1216

Reference

U. S. Fish and Wildlife Service. 15 May 1992. "Endangered and Threatened Wildlife and Plants; Determination of Endangered or Threatened Status for 15 Plants from the Island of Maui, Hawaii." Federal Register 57 (95): 20772-20787.