Haha (Cyanea acuminata)
|October 10, 1996
|Leaves are inversely lance-shaped to narrowly egg-shaped or elliptic; the upper leaf surface is green, whereas the lower surface is whitish green; the slightly hardened leaf edges contain small, spreading, pointed teeth.
|Slopes, ridges, or stream banks in mesic to wet 'ohi'a-uluhe, koa-'ohi'a, or lama-'ohi'a forest.
|Habitat degradation and destruction by feral pigs; potential impacts from military activities; potential predation by rats; competition with noxious alien plants; and risk of extinction from naturally occurring events.
Cyanea acuminata, a member of the bellflower family (Campanulaceae), is an unbranched shrub 1-6.6 ft (0.3-2.0 m) tall. The leaves, 4.3-12.6 in (109.2-320.0 mm) long and 1.2-3.5 in (30.4-88.9 mm) wide, are inversely lance-shaped to narrowly egg-shaped or elliptic. The upper leaf surface is green, whereas the lower surface is whitish green. The slightly hardened leaf edges contain small, spreading, pointed teeth. The leaf stalks are 0.8-4.0 in (20.3-101.6 mm) long. Six to 20 flowers are arranged on a flowering stalk 0.6-2.4 in (15.2-70 mm) long. The calyx lobes, 0.08-0.2 in (2-5 mm) long, are narrowly triangular. The corolla is white and sometimes tinged purplish, 1.2-1.4 in (30.5-35.6 mm) long and 0.1-0.2 in (2.5-5.1 mm) wide. The tubular portion of the flower appears almost erect to slightly curved, while the lobes are one-fourth to one-third as long as the tube and spreading. The yellow-yellowish orange, round berries are approximately 0.2 in (5.1 mm) long. The color of the petals and fruit and length of the calyx lobes, flowering stalk, and leaf stalks distinguish this species from others in this endemic Hawaiian genus. C. acuminata has been observed fruiting in February and November. Other published names considered synonymous with C. acuminata var. calycina, include C. acuminata forma latifolia, C. occultans, Delissea acuminata var. calycina, D. acuminata forma latifolia, D. acuminata var. latifolia, D. occultans, and Lobelia acuminata.
Charles Gaudichaud-Beaupre, while a pharmaceutical botanist on the vessel Uranie, collected a new lobelioid on Oahu, which he later described and named Delissea acuminata. Wilhelm Hillebrand transferred this species to the genus Cyanea in 1888, resulting in the new combination Cyanea acuminata. This is the name accepted in the current treatment of Hawaiian members of the family.
C. acuminata typically grows on slopes, ridges, or stream banks from 1,000 to 3,000 ft (304.8 to 914.4m) in elevation. The plants are found in mesic to wet 'ohi'a-uluhe, koa-'ohi'a, or lama-'ohi'a forest.
Historically, C. acuminata was known from 31 scattered populations in the Koolau Mountains.
The 15 extant populations contained a total of fewer than 100 plants in 1997. These populations occur on private land; City and County of Honolulu land; state land, including land leased by the Department of Defense for the Kawailoa Training Area; and federal land on Schofield Barracks Military Reservation and the Omega Coast Guard Station. Eleven populations each have fewer than 10 individuals, of which seven locations harbor only one or two plants each, and four populations each number from 10-40 individuals.
The major threats to C. acuminata are habitat degradation and destruction by feral pigs; potential impact from military activities; potential predation by rats; competition with the noxious alien plants Christmasberry, Koster's curse, and Maui pamakani. Additionally, the species faces the risk of extinction from naturally occurring events or through reduced reproductive vigor due to the small number of remaining individuals.
C. acuminata is potentially threatened by feral pig predation because the species is not known to be unpalatable to pigs and they favor plants from the bellflower family for food.
It is possible that rats eat the fruit of C. acuminata, a plant with fleshy stems and fruit that grows in areas where rats occur.
The noxious shrub Koster's curse is a threat to this species. Christmasberry grows in dense thickets that threaten C. acuminata. The mat-forming weed Maui pamakani also threatens this plant.
Populations of C. acuminata that occur on land leased and owned by the U.S. Army face the threat of being damaged through military activity, either by troops in training maneuvers or by the construction, maintenance, and utilization of helicopter landing and drop-off sites.
Conservation and Recovery
This species is being propagated at the Lyon Arboretum, and seeds are in storage at the National Tropical Botanical Garden.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
U.S. Fish and Wildlife Service. 1998. Recovery Plan for Oahu Plants. U.S. Fish and Wildlife Service, Portland.