Hibiscus waimeae subsp. hannerae 


Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Magnoliopsida Malvales Malvaceae

Scientific Name: Hibiscus waimeae subsp. hannerae
Species Authority: (O.Deg & I.Deg.) D.M.Bates
Parent Species:
Hibiscus waimeae A.Heller variety hannerae O.Deg. & I.Deg.
Taxonomic Source(s): Wagner, W.L., Herbst, D.R. and Lorence, D.H. 2005. Flora of the Hawaiian Islands website. Available at:

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v); C2a(i) ver 3.1
Year Published: 2015
Date Assessed: 2015-08-12
Assessor(s): Tangalin, N. & Wood, K.
Reviewer(s): Clark, M. & Bruegmann, M.
Facilitator/Compiler(s): Frances, A. & Schatz, G.E.
This taxon is Critically Endangered due to its low number of individuals, small population size, and continued decline (criterion C). There are approximately 80 mature individuals, in three severely fragmented subpopulations, with each subpopulation comprising 50 or fewer mature individuals. This taxon can be considered Critically Endangered due to its small extent of occurrence and area of occupancy, a severely fragmented population and continuing decline (criterion B). Extent of occurrence is approximately 1.6 km2. Number of locations is two because threats are different between the Limahuli subpopulations and the other two subpopulations. The Limahuli subpopulation is in the Limahuli Preserve, which is protected (fenced) and the other two subpopulations are not. The two adjacent subpopulations are close enough to not be considered severely fragmented. A variety of non-native invasive plant and animals species contribute to the decline in habitat quality as well as decline in the numbers of individuals, subpopulations, area of occupancy, and extent of occurrence.  This taxon may also be considered Endangered due to the small numbers of mature individuals (criterion D).
Previously published Red List assessments:
1998 Endangered (EN)
1998 Endangered (E)

Geographic Range [top]

Range Description: This taxon is confined to the Hawaiian island of Kauai, where three remaining subpopulations occur. Two subpopulations are in adjacent valleys, Limahuli and Hanakapiai on the north coast. A small subpopulation was discovered further south along the Napali Coast in Pohakuao Valley in 2001. An additional subpopulation in Kalihiwai appears to be extinct. This subspecies occurs between 189 and 560 m elevation.
Countries occurrence:
United States (Hawaiian Is.)
Estimated area of occupancy (AOO) - km2: 1.6
Continuing decline in area of occupancy (AOO): Yes
Estimated extent of occurrence (EOO) - km2: 1.6
Continuing decline in extent of occurrence (EOO): Yes
Extreme fluctuations in extent of occurrence (EOO): No
Number of Locations: 2
Continuing decline in number of locations: Yes
Extreme fluctuations in the number of locations: No
Lower elevation limit (metres): 189
Upper elevation limit (metres): 560
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: There are three subpopulations of this taxon. Two subpopulations are in adjacent valleys, Limahuli and Hanakapiai on the north coast of Kauai. A small subpopulation was discovered further south along the Napali Coast in Pohakuao Valley in 2001. An additional subpopulation in Kalihiwai appears to be extinct. After Hurricane Iniki in 1992, the subpopulation in Hanakapiai Valley was halved to about 25 plants. Currently there are about 20 plants in this subpopulation. The subpopulation in Limahuli Valley consists of approximately 50 mature individuals, and there are approximately 10 mature individuals in Pohakuao Valley. A portion of the Limahuli subpopulation is enclosed in an ungulate proof fence. The threat of feral pigs uniformly affects the rest of the population.
Current Population Trend: Decreasing
Additional data:
Number of mature individuals: 80 Continuing decline of mature individuals: Yes
Extreme fluctuations: No Population severely fragmented: Yes
No. of subpopulations: 1 Continuing decline in subpopulations: Yes
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: This taxon occurs in wet forest dominated by Metrosideros polymorpha.  It is typically found in ravine bottoms.
Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes

Use and Trade [top]

Use and Trade: This taxon is grown as an ornamental and is available from commercial nurseries in Hawai'i. It has fragrant flowers which is an added attraction.

Threats [top]

Major Threat(s): The lowland rainforest habitat is frequently damaged by feral pigs (Sus domesticus) and invaded by introduced invasive plants, such as Clidemia hirta, Lantana camara, Psidium guajava, Erigeron karvinskianumThese threats contribute to habitat degradation in addition to direct impacts on the individual plants.  A possible loss of pollinators and a genetic bottle neck may also contribute to the decline of this species.

Conservation Actions [top]

Conservation Actions: The species is listed as Endangered under the US Endangered Species Act and is also protected under the state of Hawaii's Endangered Species List.  It occurs on state-owned land which has some protection against development, but is managed for multiple uses including recreational hunting.  It also occurs on privately-owned land in which a portion of one subpopulation is fenced and the remainder is planned to be fenced in the near future.  The fenced area has had all feral ungulates removed and has invasive, non-native plant management as well.

Citation: Tangalin, N. & Wood, K. 2015. Hibiscus waimeae subsp. hannerae. The IUCN Red List of Threatened Species 2015: e.T33627A78767630. . Downloaded on 26 November 2015.
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