Nehe

Lipochaeta venosa

Description

This nehe (Lipochaeta venosa ) is a low-growing perennial herb with arcing, spreading stems. Its leaves are deltoid in shape with two basal lobes, and are pinnately dissected. The leaves range in length from 0.8-1.1 in (2.1-2.8 cm) and in width from 0.6-0.9 in (1.5-2.2 cm), with the upper surface sparsely hairy and the lower surface more densely so. The leaf petiole is 0.3-0.4 in (0.8-1.0 cm) long. The flower heads are solitary or in clusters of two. The outer involucral bracts are ovate in shape, up to 0.2 in (5.5 mm) long and 0.14 in (3.5 mm) wide, strigillose (bearing rough hairs pointing in the same direction), and obtuse (bluntly rounded). The bracts are chaffy and often purple near their apex. There are about five ray florets per head; the rays are ovate, up to 0.2 in (4.8 mm) long, and 0.1 in (2.8 mm) wide. The disk florets are 20 to 30 per head, with corollas up to 0.15 in (3.3 mm) long and anthers 0.06 in (1.5 mm) long. The pappus has short, deciduous awns. The achenes (or seeds) are tuberculate (having small bumps), and often spotted with purple. Achenes of the ray florets are up to 0.1 in (2.4 mm) long and 0.07 in (1.8 mm) wide, and have a small wing. Achenes of the disk florets are up to 0.9 in (2.4 mm) long and 0.06 in (1.5 mm) wide, and are wingless.

Habitat

The nehe is restricted to low-elevation cinder cones. It grows in coarse substrates developed from volcanic ash.

Distribution

The nehe is a locally evolved, or endemic species that is only known from four cinder cones in South Kohala, on the leeward, northwest flank of Mauna Kea on the island of Hawaii. The Hawaiian archipelago has an extremely large fraction of endemic species; about 89% of the indigenous flowering plants occur nowhere else in the world.

Threats

The nehe may once have had a wider habitat tolerance, but is now restricted to cinder-cone slopes because of heavy grazing pressure from cattle introduced to its habitat (which may have formerly included less-steep habitats). The nehe is also threatened by competition and habitat changes associated with species of introduced, invasive plants. Although its total population amounts to several thousand individuals, the fact that the nehe only occurs on four cinder cones makes it extremely vulnerable to extinction through catastrophic disturbances associated with volcanic eruption, a hurricane, or wildfire.

Conservation and Recovery

The nehe occurs on private land (Parker Ranch) and on the adjacent Hawaiian Home Lands. Protection of this species should be pursued through purchase of the private land and establishment of an ecological reserve, or the negotiation of a conservation easement. Management of the habitat of the endangered nehe requires the control of fire. The abundance of invasive plants must also be reduced, especially the fountaingrass (Pennisetum setaceum ). Grazing by introduced mammalian herbivores, especially cattle, should be prevented by erecting fences around the critical habitat of the nehe. The State Division of Forestry and Wildlife has erected protective fences around some of the populations to protect the plant from ungulates. Its populations should be monitored, and research undertaken into its basic biology and the environmental factors that are constraining its population size.

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/

U.S. Fish and Wildlife Service
Pacific Islands Fish and Wildlife Office
300 Ala Moana Boulevard, Room 3-122
P. O. Box 50088
Honolulu, Hawaii 96850
Telephone: (808) 541-3441
Fax: (808) 541-3470

References

Conservation Management Institute. 13 March 1996." Lipochaeta venosa. " Endangered Species Information System, Virginia Tech, Blacksburg. (http://fwie.fw.vt.edu/WWW/esis/lists/e701006.htm). Date Accessed: July 6, 2000.

U. S. Fish and Wildlife Service. 2000. "The Recovery Plan for Lipochaeta venosa & Isodendrion hosakae." U. S. Fish and Wildlife Service: Threatened and Endangered Species: Endangered Plants in Hawai'i. (http://www.r1.fws.gov/pacific/wesa/lipoven_isodhasidx.html). Date Accessed: July 6, 2000.