Haha

Cyanea hamatiflora ssp. carlsonii

Description

This haha, Cyanea hamatiflora ssp. carlsonii, a palmlike tree, grows 9.8-26 ft (3.0-7.9 m) tall and has alternate, stalkless leaves 20-31 in (50.8-78.7 cm) long and 3.0-5.5 in (7.6-14.0 cm) wide. Clusters of five to 10 flowers have a main stalk 0.6-1.2 in (1.5-3.0 cm) long; each flower has a stalk 0.2-0.5 in (0.5-1.3 cm) long. The hypanthium is topped with five small, narrow calyx lobes. The magenta petals are fused into a one-lipped tube 2.3-3.1 in (5.8-7.9 cm) long and 0.2-0.4 in (0.5-1.0 cm) wide, with five downcurved lobes. The purplish red berries are topped by the persistent calyx lobes. This subspecies is distinguished from C. hamatiflora ssp. hamatiflora, the only other subspecies, by its long flower stalks and larger calyx lobes. The species differs from others in the genus by its growth habit, its stalkless leaves, the number of flowers in each cluster, and the size and shape of the corolla and calyx. This taxon was observed in flower during December of 1980 and August of 1995. Seeds were collected by Hawaii Division of Forestry and Wildlife (DOFAW) in October of 1991 and November of 1995. No other life history information is currently available.

Habitat

This species typically grows in 'ohi'a-dominated montane wet forests at elevations between 4,000 and 5,700 ft (1,219 and 1,737 m). Associated species include kawa'u, pilo, and naio.

Distribution

This subspecies is known only to have occurred at two sites on the island of Hawaii, on the western slope of Hualalai and the southwestern slope of Mauna Loa.

The two extant populations, located on private and state land at Honuaulu Forest Reserve and Keokea, are about 28 mi (87 km) apart and contain approximately 14 individuals. Forty-five individuals were outplanted on the Honuaulu Forest Reserve.

Threats

Alien plant invasion represents a serious threat to the long-term survival of C. hamatiflora ssp. carl-sonii. Banana poka, an invasive alien weed, negatively impacts C. hamatiflora by competing for nutrients, water, and light. Grazing and trampling by domestic and escaped cattle and rooting by pigs degrade the habitat and open sites conducive for alien plant establishment. Rats and alien birds may eat the juicy fruits, reducing the potential numbers of successive individuals. The small remaining numbers of individuals and their limited and scattered distribution are serious threats because a single natural or human-induced event may have catastrophic effects on the few surviving plants. Seeds collected by DOFAW in 1991 had little or no insect damage, but seeds collected in 1995 were heavily damaged by an undetermined species of caterpillar. Reproductive vigor may be depressed by a limited gene pool.

Conservation and Recovery

The National Tropical Botanical Garden has propagated this species. Seeds planted at Volcano Rare Plant Facility have not germinated, and seeds acquired by Lyon Arboretum from storage were not viable. Attempts are being made to obtain new seed. In 1993, 22-27 individuals were planted within two exclosures at Honuaulu Forest Reserve. Currently, 21 plants remain alive in the first and 23 in the second. One individual was planted outside the ex-closures and is surviving. Three unhealthy plants were planted near Honomalino, but all died. Of several individuals planted at Puu Waawaa, six have survived.

Current populations need to be protected from ungulates, and banana poka and other alien species controlled, to the extent possible, within the taxon's habitat. Propagation and outplanting efforts should be encouraged and continued.

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/

Senior Resident Agent Office
U.S. Fish and Wildlife Service
300 Ala Moana Boulevard, Room 7-235
P.O. Box 50223
Honolulu, Hawaii 96850-5000
Telephone: (808) 541-2681
Fax: (808) 541-3062

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.