CPC National Collection Plant Profile

Hibiscadelphus distans


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CPC National Collection Plant Profile

Hibiscadelphus distans

Common Names: 
hau Kuahiwi, Kauai hau kuahiwi
L. Bishop & Herbst
Growth Habit: 
Tree, Shrub
CPC Number: 


Profile Links
 Fish & WildLife

Hibiscadelphus distansenlarge
Image Owner: National Tropical Botanical Garden

Hibiscadelphus distansenlarge
Photographer: S. Perlman
Image Owner: National Tropical Botanical Garden

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

Hibiscadelphus distans

There are seven known species of Hibiscadelphus, which is a genus that is endemic to Hawaii. Five of those seven species are now extinct in the wild, although two of those are surviving in cultivation. H. distans is one of the two remaining Hibiscadelphus species with remaining wild populations. However, this species, too, is on the verge of extinction. In 2001, less than 200 individuals among two populations were recorded (USFWS 2001) and, as of 2002, this number had declined to just 30 plants in a single population (K. Wood, pers. comm. 2002).

H. distans, a member of the hibiscus family (Malvaceae) is a shrub or small tree that grows up to 5 meters tall. Plants have a grayish brown trunk, graceful branching habit, and broadly ovate (heart-shaped) leaves. The upper surfaces of the leaves are sparsely pubescent with the under surface more densely pubescent (Wagner et. al., 1990). The greenish yellow tubular flowers of H. distans are erect and solitary, and turn maroon with age. Unlike many closely related members of the Hibiscus family, these flowers are bilaterally symmetrical. The seedpods are woody capsules with five sections containing seeds that are yellowish brown and pubescent (USFWS 1996).

Distribution & Occurrence

State Range
State Range of  Hibiscadelphus distans
  H. distans is found in dry forests at approximately 350 meters elevation. It is located above Koai’e Stream on Kaua’i (Wagner et al. 1999).

Associated species of H. distans include Aleurites moluccana (kukui), Artemisia kauaiensis (no common name [NCN]), Psydrax odoratum (alahee), Diospyros sandwicensis (lama), Lipochaeta connata (nehe), Myrsine sp. (kolea), Nototrichium sandwicense (kului), Pouteria sandwicense (alaa), Triumfetta semitriloba (Sacramento bur) and Sapindus oahuensis (lonomea). The ground cover is mostly alien grasses.

  H. distans is endemic to Kaua’i. After hurricane Iniki a population of approximately 50 individuals was extirpated in Hipalau valley, one of only two sites where H. distans occur. The other known population in Koai`e Canyon is now down to approximately 30 individuals (K. Wood, pers. comm. 2002).

Number Left
  Number of Populations: 1 recorded in 2002
Number of Plants: 30 recorded in 2002 (K. Wood, pers. comm. 2002)


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

State/Area Protection
  State/Area Rank Status Date  
  Hawaii S1 4/11/2002  

Conservation, Ecology & Research

Ecological Relationships
  Pollination and seed dispersal mechanisms for H. distans are unknown (USFWS 1996).

H. distans is found in Lower Koaie Canyon within a highly degraded native mesic forest. In this location, the plants receive full sun in the summer and no direct sun in the winter. Lower Koaie Canyon receives approximately 60 inches of rain annually.

  Threats to H. distans include feral goats, alien plants such as Lantana camara (lantana), human disturbance, natural occurring events such as fires and hurricanes, insect pests such as the exotic pink bollworm (Pectinophora gossypiella), and potentially genetic problems such as inbreeding effects (USFWS 1996).

Current Research Summary
  Seeds of H. distans have been tested by the National Seed Storage Laboratory (NSSL), and the National Tropical Botanical Garden (NTBG), finding that they are orthodox and can tolerate freezing and drying. The laboratory germination time was two months (Yoshinaga 2002).

Current Management Summary
  Seeds of H. distans are easily propagated if the seeds are available and undamaged. The USFWS has also conducted research on the pollinators of H. distans, finding that they may be capable of self-pollination. However, cross-pollination may be important for maintaining the species’ long term genetic variability (USFWS 1996).

NTBG currently has ex situ holdings of seeds in its seed bank, there are 11 plants in the nursery and 48 individuals in the botanical garden. The 11 individuals represent the single population. The seeds and 48 plants in the botanical garden represent a population that was lost, in addition to the remaining population.

Research Management Needs
  1. Map genetic diversity in the surviving populations of H. distans.
2. Test the influence of weeding and fencing on populations of H. distans.
3. Conduct pollination biology and seed dispersal studies on H. distans.
4. Secure wild populations through on-site management.
Recommendations derived from M.H. Chapin, and M. Maunder.

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


Books (Single Authors)

Sohmer, S.H.; Gustafson, R. 1987. Plants and Flowers of Hawaii. Honolulu, HI: University of Hawaii Press. 160p.

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.

Yoshinaga, A. (2002). Seed storage characteristics of Hawaiian species. [Web site] University of Hawaii, Honolulu, Hawaii 96848. http://www.hawaii.edu/scb/seed/seedtabl.html. Accessed: 2002.

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.

Bishop, L.E; Herbst, D.R. 1973. A new Hibiscadelphus (Malvaceae) from Kauai. Brittonia. 25: 290-293.

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.

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

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.

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

USFWS. 1985. Endangered Classification Proposed for Four Plants. Endangered Species Technical Bulletin. 10, 8: 4.

USFWS. 1985. Proposed rule to determine endangered status for Hibiscadelphus distans (Kauai hau kuahiwi). Federal Register. 50, 136: 28873-28876.

USFWS. 1985. Public Hearings and Reopening of Comment Period on Proposed Endangered Status for Abutilon menziesii (ko`oloa 'ula), Hibiscadelphus distans (Kauai hau kuahiwi), Mezoneuron kavaiense (uhiuhi), and Scaevola coriacea (dwarf naupaka). Federal Register. 50, 202: 42196-42197.

USFWS. 1986. 18 Plants Proposed for Listing Protection. Endangered Species Technical Bulletin. 11, 5: 1-13.

USFWS. 1986. Determination of endangered status for Hibiscadelphus distans (Kauai hau kuahiwi). Federal Register. 51, 82: 15903 - 15905.


USFWS. 1996. Recovery plan for Hibiscadelphus distans. Portland, OR: U.S. Fish & Wildlife Service. p.42.

  This profile was updated on 3/4/2010
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