CPC National Collection Plant Profile

Hibiscadelphus giffardianus

D. Lorence

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CPC National Collection Plant Profile

Hibiscadelphus giffardianus

Common Name: 
hau Kuahiwi
Growth Habit: 
CPC Number: 


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 Fish & WildLife

Hibiscadelphus giffardianusenlarge
Photographer: D. Lorence
Image Owner: National Tropical Botanical Garden

Hibiscadelphus giffardianus is Not Sponsored
Primary custodian for this plant in the CPC National Collection of Endangered Plants is: 

Hibiscadelphus giffardianus

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.

Distribution & Occurrence

State Range
State Range of  Hibiscadelphus giffardianus
  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.

  A single tree of H. giffardianus was found in 1911 in Kipukapuaulu (1,310 m) on the eastern slopes of Mauna Loa, Hawai’i. Today it is believed that H. giffardianus is extinct in the wild (Wagner et. al., 1990).

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


Global Rank:  
Guide to Global Ranks
Federal Status:  
Guide to Federal Status
Recovery Plan:  

State/Area Protection
  State/Area Rank Status Date  
  Hawaii SH 4/11/2002  

Conservation, Ecology & Research

Ecological Relationships
  None known.

  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. giffardianus is also at risk of extinction due to a restricted gene pool from a single parent. Cattle were known in the area before Hawai’i Volcanoes National Park (HVNP) became a National Park and probably had a large negative influence on the habitat as well.

Current Research Summary
  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 Hawai’i 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.

Current Management Summary
  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.

Research Management Needs
  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).

Ex Situ Needs
  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.


Books (Single Authors)

Rock, J.F. 1913. The indigenous trees of the Hawaiian Islands. Honolulu, HI: Published privately. 512p.

Wagner, W.L.; Bruegmann, M.M.; Herbst, D.R; Lau, J.Q.C. 1999. Hawaiian Vascular Plants at Risk: 1999. Honolulu, HI: Bishop Museum Press Honolulu.

Wagner, W.L.; Herbst, D.R.; Sohmer, S.H. 1999. Manual of the flowering plants of Hawai'i--Revised Edition. Honolulu, HI: University of Hawaii Press and Bishop Museum Press. 1853p.

Books (Sections)

Funk, V.A.; Wagner, W.L. 1995. Biogeography of seven ancient Hawaiian plant lineages. In: Wagner, W.L.; Funk, V.A., editors. Hawaiian Biogeography: Evolution on a Hot Spot Archipelago. Smithsonian Institution Press. Washington, D.C.

Kartesz, J.T. 1999. A synonymized checklist of the vascular flora of the U.S., Canada, and Greenland. In: Kartesz, J.T.; Meacham, C.A., editors. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden. Chapel Hill, NC.

Electronic Sources

Gustafson, R.J. Hawaii's Unique and Vanishing Flora: A Photographic Exhibition. [Web site] ¬ The Natural History Museum of Los Angeles County Foundation. http://www.nhm.org/research/botany/Hawaii_Vanishing_Flora/home.html. Accessed: 2002.

NatureServe. (2008). NatureServe Explorer: An online encyclopedia of life [web application]. [Internet].Version 7.0. NatureServe, Arlington, Virginia. http://www.natureserve.org/explorer. Accessed: (June 17, 2008).

USFWS. (2001). Unpublished data. U.S. Fish and Wildlife Service, Honolulu, Hawaii 96817. Accessed: 2001.

Journal Articles

Baker, J.K. 1980. The plant genus Hibiscadelphus in Hawai'i. The Cooperative National Park Resources Study Unit, Hawaii: Technical Report. 34: 1-31.

Baker, J.K.; Allen, S. 1977. Hybrid Hibiscadelphus (Malvaceae) in the Hawaiian Islands. Pacific Science. 31, 3: 285-291.

Baker, K.; Allen, S. 1976. Hybrid Hibiscadelphus (Malvaceae) from Hawaii. Phytologia. 33, 4: 276.

Carr, G.D.; Baker, J.K. 1977. Cytogenetics of Hibiscadelphus (Malvaceae): A Meotic Analysis of Hybrids in Hawaii Volcanoes National Park. Pacific Science. 31, 2: 191-194.

Degener, I.; Degener, O. 1977. Hibiscadelphus number KK-HX-1: An international treasure in Hawaii. Phytologia. 35, 5: 385-396.

Ellshoff, Z.E. 1991. The Rarest Hawaiian Members of the Hibiscus Family. National Tropical Botanical Garden: The Bulletin. 21, 3: 7-12.

Fagerlund, G.O. 1944. Hau kuahiwi, sole survivor. Paradise of the Pacific [Honolulu]. 56, 1: 21, 32.

Hobdy, R.W. 1984. A re-evaluation of the genus Hibiscadelphus (Malvaceae) and the description of a new species. Occasional Papers of the Bernice P. Bishop Museum. 25: 1-7.

Lorence, D.H.; Wagner, W.L. 1995. Another New, Nearly Extinct Species of Hibiscaldelphus (Malvaceae) from the Hawaiian Islands. Novon. 5, 2: 183-187.

Radlkofer, L.; Rock, J.F. 1911. New and noteworthy Hawaiian plants. Hawaii, Board Agric. Forest. Bot. Bull. 1: 1-15.

USFWS. 1976. Proposed Endangered Status for 1700 U.S. Plants. Federal Register. 41: 24523-24572.

USFWS. 1995. Proposed endangered status for thirteen plants from the island of Hawaii, state of Hawaii. Federal Register. 60, 185: 48377-48392.

USFWS. 1996. Determination of endangered status for thirteen plants from the island of Hawaii, state of Hawaii. Federal Register. 61, 198: 53137-53153.

USFWS. 2002. Designations of Critical Habitat for Plant Species From the Island of Hawaii, Hawaii. Federal Register. 67, 102: 36968-37016.


USFWS. 1998. Big Island II: Addendum to the Recovery Plan for the Big Island Plant Cluster. Portland, OR: U.S. Fish & Wildlife Service. p.80 + appendices.

  This profile was updated on 3/4/2010
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