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Plant Profile

Kilauea Hau Kuahiwi (Hibiscadelphus giffardianus)

Closeup of leaf and flower bud. Notice the five-angled shape of the leaf. Photo Credit: D. Lorence

Global Rank: GH - Possibly Extinct
Legal Status: Federally Endangered
Family: Malvaceae
State: HI
Nature Serve ID: 140440
Lifeform: Tree
Date Inducted in National Collection: 07/09/1992

Description:

There are seven known species of Hibiscadelphus, which is a genus that is endemic to Hawaii. Four of those seven species are now extinct. H. giffardianus, one of the remaining 3 species, was discovered in 1911, and is known from only one tree in the wild. In 1930, this tree died, but one cutting taken from it survived. This remaining cutting died in cultivation in 1940, but not before yet another cutting was taken from it. This cutting grew to maturity, and the 9 known individuals of this species are descendants from it. (Baker & Allen 1977) A member of the hibiscus family (Malvaceae), H. giffardianus is a tree approximately 7 meters tall that exists only in cultivation. Trunks of this tree grow up to 30 centimeters in diameter and are whitish in color. The leaves of H. giffardianus are heart-shaped, 10 to 30 centimeters long with a broad tip. Flowers are solitary with a corolla that is grayish green externally and dark magenta within and 5 to 7 centimeters long. Five to seven filamentous bracts are borne below each flower and the calyx is pouch-like. The fruit of H. giffardianus are woody with star shaped hairs. This species can be differentiated from others in this endemic Hawaiian genus by its flower color, flower size, and filamentous bracts. Most cultivated trees of H. giffardianus are located at Volcanoes National Park.

Where is Kilauea Hau Kuahiwi (Hibiscadelphus giffardianus) located in the wild?

Habitat:

H. giffardianus was restricted to mixed montane mesic forests at elevations between 1,200 and 1,310 meters (U.S. Fish and Wildlife Service [USFWS] 1998). This species formerly grew on the eastern slopes of Mauna Loa. Today it is believed to be extinct in the wild, existing only in cultivation (Wagner et al. 1999). Associated species of H. giffardianus include Metrosideros polymorpha (ohia), Acacia koa (koa), sapindus saponaria (ae), Diplazium sandwicianum (hoio), Coprosma sp. (pilo), Pipturus albidus (mamaki), Psychotria sp. (kopiko), Nestegis sandwicensis (olopua), Melicope sp. (alani), Dodonaea viscosa (aalii), Myoporum sandwicense (naio), and introduced grasses.

Distribution:

A single tree of H. giffardianus was found in 1911 in Kipukapuaulu (1,310 m) on the eastern slopes of Mauna Loa, Hawaii. Today it is believed that H. giffardianus is extinct in the wild (Wagner et. a

States & Provinces:

Kilauea Hau Kuahiwi can be found in Hawaii

Which CPC Partners conserve Kilauea Hau Kuahiwi (Hibiscadelphus giffardianus)?

National Tropical Botanical Garden

Not Sponsored

Assigned 06/09/17

CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.

Conservation Actions

Nature Serve Biotics

05/02/2017

The only known wild tree of this species was discovered in 1911 within what is now Hawaii Volcanoes National Park on the island of Hawaii. The tree died in 1930. Its descendents remain in cultivation and some of these have been planted out at the site of the original wild tree. The site was grazed by cattle in the early 1900's. Current threats to the outplanted population are feral pigs, alien plants, and potential volcanic activity.

01/01/2010

Threats to H. giffardianus include: predation by rats leaf damage by Sophonia rufofacia (two spotted leaf hopper)and yellowing by the native bug Hylalopeplus pellucidus competition from alien grasses and habitat changes from volcanic activity H.

01/01/2010

Number of Populations: 0 (USFWS 2001) Number of Plants: 9 in cultivation (USFWS 2001) 16 recorded in 1997 (USFWS 1998)

01/01/2010

In the 1970's, a number of individuals studied the effects of hybridization between this species the closely related, also endangered, Hibiscadelphus hualalaiensis. (Baker & Allen 1976, Baker & Allen 1977, Carr & Baker 1977, Degener & Degener 1977) These two species did not naturally occur together, but had been planted near each other in Hawaii Volcanoes National Park during early conservation efforts. It was eventually determined that this situation resulted in hybridization between the two species. The decision was made to remove H. hualalaiensis from the park in order to maintain the genetic integrity of both species. Today, both of these species are maintained in cultivated settings.

01/01/2010

Hawai'i Volcanoes National Park (HVNP) fenced the outplanted Kipukapuaulu population in the 1960s and weed control has been undertaken. There has also been some efforts made at rodent trapping. HVNP has 5 plants in their nursery. Volcano Rare Plant Facility (VRPF) has 9 plants in their facility, and the National Tropical Botanical Garden (NTBG) has 2 plants. NTBG currently has ex situ holdings of four plants that are growing in the grounds of the botanical garden.

01/01/2010

1. Outplant new populations in areas of reduced threat. Prior to outplanting, the sites should be fenced, free of weeds and free of rats and feral ungulates. Before weeding and fencing are utilized, testing should be done on their effects. 2. Reduce threat from rodent predation especially around fenced populations and investigate the use of rodenticide. 3. Control insect damage especially for the two-spotted leafhopper. More research is needed on spraying, treatment, and other more suitable methods. 4. Conduct pollination biology and seed dispersal studies on H. giffardianus. Recommendations derived from M.H. Chapin, M. Maunder, USFWS (1998).

01/01/2010

1. Establish secure ex situ stocks with full founder representation. 2. Develop proper horticultural protocols and pest management for H. giffardianus. 3. Survey ex situ holding and conduct molecular fingerprinting. Recommendations derived from M.H. Chapin and M. Maunder.