Haha (Cyanea truncata)
|Listed||March 28, 1994|
|Description||Unbranched or sparsely branched shrub with small sharp prickles, oval leaves, and clusters of eight to 40 white flowers with magenta stripes.|
|Habitat||Windward slopes in mesic to wet forests.|
|Threats||Competition from alien plants, habitat destruction by feral pigs, limited numbers.|
This haha, Cyanea truncata, is an unbranched or sparsely branched shrub covered with small sharp prickles. The oval leaves, which are widest above the middle area, are 8-24 in (20.3-61 cm) long and 4-10 in (10.2-25.4 cm) wide. The leaves are lined with hardened teeth along the margins. The upper surface of the leaf is hairless; the lower surface is hairy, has sparse projections, and is pale green. Clusters of eight to 40 white flowers with magenta stripes are produced on horizontal or hanging stalks 2-12 in (5.1-30.5 cm) long. Each slightly curved flower is 1.3-1.7 in (3.3-4.3 cm) long, about 0.3 in (7.6 mm) wide, and has spreading corolla lobes that are one-quarter to one-half as long as the flower. The fruits are round orange berries about 0.4 in (1 cm) long that contain many tiny seeds. C. truncata is distinguished from other members of this genus by the length of the flower cluster stalk and the size of the flowers and flower lobes.
C. truncata was seen in flower in December 1919 and November 1980, the last time the species was observed before feral pigs extirpated the population.
C. truncata typically grows on windward slopes in mesic to wet forests at elevations of 800-1,300 ft (243.8-396.2 m). Associated plants include koki'o ke'oke'o, lama, 'ohi'a, kukui, ha'iwale, ma'aloa, papala kepau, and 'awa.
C. truncata was known historically from Punaluu, Waikane, and Waiahole in the northern Koolau Mountains of Oahu. These sites have not been recently surveyed because of their inaccessibility, but it is known that suitable habitat is present. One population of at least two individuals was known to exist in Hidden Valley, a drainage northwest of Kaaawa Valley that terminates at Kaaawa Point in the Koolau Range; however, this occurrence was destroyed by feral pigs.
In 1991 John Obata discovered 20 immature lobeloids growing on private land along a gully floor farther upstream from the site of the destroyed population. This was thought to be the only known population of C. truncata. An individual from this sterile population was salvaged from pig-damaged areas in 1991 and flowered in June 1993. However, this individual turned out to be Rollandia crispa, not C. truncata. A site visit in July 1993 determined that all the plants thought to be C. truncata were actually R. crispa. No individuals of C. truncata were located, though it is possible that juvenile plants could be found in the valley floor. At present, no confirmed population exists, although the species is not considered extinct.
The major threats to C. truncata are 1) habitat degradation and predation by feral pigs, 2) suspected predation by rats and slugs, 3) competition with the invasive plants Koster's curse and strawberry guava, and 4) a risk of extinction due either to random natural episodes or to reduced reproductive vigor. At best, only a tiny number of individuals remain.
Conservation and Recovery
No specific conservation measures have been undertaken for C. truncata. Surveys of appropriate habitat in historical locations are needed to determine if any other extant populations of this plant exist. To prevent extinction of this species, cultivated propagation should be initiated immediately if extant individuals are located.
Once adequate propagated material is available and appropriate fencing, rat control, and weed control are under way in the areas of any remaining naturally situated populations, these occurrences should be enhanced by outplanting. Establishment of new populations within the historical range of C. truncata should be initiated in areas that are managed to minimize the impacts of feral ungulates, rats, and alien plants.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
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
U. S. Fish and Wildlife Service. 28 March 1994. "Endangered and Threatened Wildlife and Plants: Endangered Status for 11 Plant Species from the Koolau Mountain Range, Island of Oahu, HI." Federal Register 59:14482-14492.