Hibiscus brackenridgei
Plant Family
Malvaceae
Binomial Name
Hibiscus brackenridgei A. Gray
Synonymous Binomial Names
None.
Subspecies
Two subspecies are currently recognized:
H. b. ssp. brackenridgei, referred to as Brackenridge’s rosemallow, is a short lived perennial that grows in the form of a sprawling shrub to an erect tree and found in dry forests and low shrub lands at elevations of 120–790 m (400–2,600 ft ) above sea level on Molokai, Lanai, Maui, and the island of Hawaii. Unless otherwise indicated this is the subspecies referred to on this web page simply as Hibiscus brackenridgei.
H. b. ssp. mokuleianus, referred to as Mokulei rosemallow, is a tree that was found in dry habitats on Kauai and the Waianae Range on Oahu. It is now extinct (Keir 2018a).
Common (Vernacular) Names
English: Hawaiian hibiscus, yellow hibiscus, native yellow hibiscus, Brackenridge’s rosemallow
Hawaiian: Maʻo hau hele, pua aloalo, aloalo
Hibiscus brackenridgei is the Official State Flower of Hawaii. The history of this designation is available in a NETSTATE.com article (Anonymous 2020).
Plant Characteristics
Endemicity. This species is or was found on all the main Hawaiian islands except Ni’ihau and Kaho’olawe in dry forests and shrub lands at elevations from 400 to 2,600 feet (Wagner, Herbst and Sohmer 1990). Other Fish and Wildlife Service references (FWS 2003, 2020 et al.) indicate that the species was reported to have been present on Kaho’olawe. It is now extinct on Kauai.
Growth Habit. An erect shrub or small tree up to five meters tall. The leaves are green, arranged alternately, toothed at the edges, hairy on the undersides and hairless on the tops. Mature leaves on the middle of the branches have three to seven lobes similar to a maple leaf. The younger trees have smooth tan trunks that transition to a wrinkled appearance as they age.
Flowers. The flowers form singly or in small clusters at the ends of the branches and are 10 to 15 cm (4 to 6 inches) wide. The have five bright yellow petals, a yellow staminal column and centers sometimes with red or maroon splotches. Most bloom in the winter through early summer but small numbers of flowers may appear throughout the year. They generally open in the afternoon, close in late evening and have no fragrance.
 Flower of Hibiscus brakenridgei ssp. brakenridgei |
Seeds. The seeds form in oval capsules 1-2 cm long, covered with soft hairs and ending with with spine-like beaks. When they are dry and mature they turn to a tan color and open to release the seeds that are about 6mm long, kidney-shaped, and covered with fine hairs.
 Seeds of Hibiscus brakenridgei ssp. brakenridgei |
Conservation Status
Hibiscus brackenridgei is now rare in all of the areas where it is found and the remaining populations are severely fragmented and declining.
In 1999 there were known to be 12 populations of the species in Hawaii consisting of 311-364 individual plants (FWS 1999). In 2017 an assessment found that there were only 20 mature plants and about a total 50 individuals left in the wild.
These and other endangered Hawaiian plant species have been affected by or are currently threatened by the following factors, to differing degrees: habitat degradation and/or predation by pigs, goats, deer, sheep and cattle; invasion and competition from naturalized, introduced vegetation; habitat loss from fires; erosion of substrate produced by hurricanes, weathering, or human-or animal-caused disturbance; human impacts from military and recreational activities; alien insect infestations; predation by alien snails and slugs; and the potential for extinction from random naturally occurring events because of small population size and/or limited distribution (FWS 1990).
IUCN Red List of Threatened Species, Version 2020-2. Hibiscus brackenridgei has a declining population and is listed as critically endangered (CR) by the IUCN (Keir 2018b). Fires, fire suppression, invasive non-native/alien species/diseases are indicated as primary threats to its survival.
Hibiscus brackenridgei subspecies brackenridgei has a declining population and is listed as critically endangered (CR) by the IUCN (Bruegmann, Caraway and Keir 2018). Fires, fire suppression, livestock farming and ranching, invasive non-native/alien species/diseases are indicated as primary threats to its survival. The taxon is now considered extremely rare, with a total known wild population of less than about 20 mature plants and fifty individuals in five subpopulations on the islands of Maui, Lanaʻi, and Hawaiʻi.
Hibiscus brackenridgei subspecies molokaiana is now extinct (Keir 2018a).
CITES Listing: Hibiscus brackenridgei is not listed on any of the CITES Appendices.
Federal Status: Hibiscus brackenridgei was listed as an Endangered Species by the U.S. Fish and Wildlife Service on November 10, 1994 and this listing status now applies wherever it is found (FWS 2020).
Hawaii Status: Both subspecies of Hibiscus brackenridgei are listed by the Hawaii Department of Land and Natural Resources, Division of Forestry and Wildlife as Endangered Species (DOFAW 2020).
Uses and Cultivation
This native Hawaiian hibiscus was grown as an ornamental by the early Hawaiians (Handy, Handy, Pukui, 1991) and continues to find limited use in landscaping as a container or specimen plant, in screening and hedges in sunny areas. It is now rarely available from nurseries on Hawaiʻi Island. In our area specimen plants are seen in the front yards of several homes. The plant grows quickly but is shallow rooted and tends to be knocked over by strong trade winds and tropical storms.
Traditional Medicinal Uses. None reported.
Propagation
From Seeds. With adequate control of mealy bugs and other pests some of the flowers will often set seeds. A small percentage of these will germinate within a month, others may germinate over a period of a year. Scarification of the seeds may hasten germination of the seeds.
We don’t know if this species is self-sterile. All of our plants were grown from cuttings from a single plant. Seeds produced on these plants may hybrids resulting from cross pollination with other ornamental hibiscus species blooming in the area.
 New Seedling of Hibiscus brackenridgei |
The seedlings grow rapidly. The photo below is the same seedling three months after emergence.
 Hibiscus brakenridgei Seedling Three Months Old |
From Cuttings: This species is easy to propagate from cuttings made from the thicker hardwood branches with tan bark. Do not use thinner cuttings with green bark on the end to be rooted. Place the cuttings in water changed frequently to prevent rot. Roots generally form in 2-3 weeks. The use of rooting hormones is not required. Transfer the rooted cuttings to containers with well draining potting soil. Keep them trimmed to prevent leggy growth and encourage branching. In 2-3 months they should be ready for out planting.
 Fresh Cuttings of Hibiscus brakenridgei for rooting |
The cuttings also grow quickly. This specimen is ready for out planting within about two months after rooting and transfer to potting soil. The red permit tag is required for commercial sale of endangered plants in Hawaii.
 Rooted Cutting of Hibiscus brakenridgei |
The Hawaiian Native Plant Propagation Database (CTAHR 2020) provides detailed information on propagation and care of this species.
Improved Cultivars
No improved cultivars are known to us.
Pests and Diseases
Maʻo hau hele is subject to many pests and most severely affected by alien invasive pest species. We believe these pests, particularly mealy bugs, prevent or reduce seed production may be major contributors to the declines in wild populations and potential extinction of this species.
Mealy Bugs. In our growing area mealy bugs are by far the most serious, pervasive and recurrent pest infesting this species. They can infest all above ground parts of the plant but are most common on the undersides of leaves and the branch tips. The infested parts become yellow, deformed and eventually die back. Severe infestations will kill the plants. Ants must be controlled to reduce or prevent infestations of both mealy bugs and scale insects. We have repeatedly observed yellow crazy ants (Anoplolepis gracilipes) a highly invasive pest species that is difficult to control, “farming” mealy bugs on this hibiscus. The ants have a mutualistic relationship with the bugs, moving, tending and protecting them against their natural enemies and consuming honeydew produced by the bugs (Ness and Bronstein 2004). Other studies have shown that, in environments where A. gracilipes was removed, the density of scale insects on other species of plants dropped by 67% within 11 weeks, and to zero after 12 months (Abbott and Green 2007).
Below are a series of photographs and videos of mealy bugs and ants on Hibiscus brackenridgei subspecies brackenridgei grown at our facility.
 Mealy Bugs on Hibiscus brackenridgei Tended by Anoplolepis gracilipes |
 Mealy bug infestation on Hibiscus brackenridgei leaf |
 Mealy Bug Damage to Branch Tip of Hibiscus brackenridgei |
The following videos are of mealy bug nymphs on a Hibiscus brackenridgei plant growing in cultivation at Discovery Harbour, Hawaii. The first video shows the emergence of nymphs from eggs within the cottony webbing material produced by the female. The second video shows the mobility of nymphs or “crawlers”.
Aphids may infest these plants and are most commonly observed on the young shoots and leaves. They can be controlled by use of insect soaps but usually do not cause significant damage.
Hibiscus Mites. The hibiscus leaf-crumpling mite (Eriophyes hibisci) is present at our site and infests the widely planted ornamental Chinese red hibiscus (Hibiscus rosa-sinensis) cultivars and severely damages the native Hibiscus kokio. We have not observed this pest on Hibiscus brackenridgei grown at our site, even in close proximity to the other infested hibiscus species. Refer to the Pacific Pests and Pathogens – Mini Fact Sheet (ACIAR 2020) for additional information.
Chinese rose beetles (Adoretus sinicus) chew holes in the leaves and cause significant defoliation and stress. These are best controlled by trapping and manual removal (Lyon 2020).
White Flies. Several species of white flies including the newly introduced giant white fly (Aleurodicus dugesii Cockerell) are present in our area. Biological controls and removal by high pressure water spraying may be effective. The use of broad spectrum insecticides is not recommended as they may be harmful to the natural enemies of white flies (Heu et al. 2004).
Spider mites are reportedly common pests at other sites (UH 2009).
Root knot nematodes can affect this species and are reportedly controlled by planting African marigolds in the area (UH 2009). These nematodes are found in our area and have not been observed the roots of our plants.
Mildew. Plants grown in the shade may be subject to mildew.
Rot. Over watering can cause root rot and the rapid demise of these plants.
Invasiveness Potential
Global Invasive Species Database. This species was not found on the Global Invasive Species Database (GISD 2020).
Hawaii-Pacific Weed Risk Assessment (HWPRA). No assessment of this species has been performed (HPWRA 2020).
Hibiscus brackenridgei is a Pono Plant, a good choice for planting in Hawaii.
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Toxicity and Precautions
We found no information indicating that this plant poses toxicity hazards or requires special precautions in handling.
Plants and Seeds for Sale
Availability
We have a commercial permit from the Hawai`i Division of Forestry and Wildlife (DOFAW) to sell cuttings and potted specimens of this species in Hawaii. These may be ordered through our online store. All plants sold in Hawai`i must be affixed with the red tag issued by DOFAW and we are required to maintain records of all sales and donations of seeds and plants of this species. We currently cannot ship seeds, cuttings or plants of this species to locations outside the state of Hawai`i.
Seeds. Very limited quantities of seeds from this species may be available from our online store.
Nursery Stock. Seed grown plants and rooted cuttings produced in sustainable artificial cultivation at our facility are available for local sale. Certified plants may be shipped to other locations in Hawa`i.
Improved cultivars are not available.
References
Abbott KL, Green PT. 2007. Collapse of an ant-scale mutualism in a rainforest on Christmas Island. Oikos. 116 (7): 1238–1246. https://doi.org/10.1111/j.0030-1299.2007.15629.x.
ACIAR (Australian Centre for International Agricultural Research, Australian Government). Pacific Pests and Pathogens – Fact Sheets. Hibiscus mite (266). http://www.pestnet.org/fact_sheets/hibiscus_mite_266.htm [Accessed 03 December 2020).
Anonymous. 2020. Adoption of the Hawaii State Flower. https://www.netstate.com/states/symb/flowers/hi_yellow_hibiscus.htm [Accessed 20 December 2020].
Bruegmann M, Caraway VL, Keir M. 2018. Hibiscus brackenridgei subsp. brackenridgei. The IUCN Red List of Threatened Species 2018: e.T30775A78767280. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T30775A78767280.en. Downloaded on 03 December 2020.
CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). Appendices I, II, and III valid from 4 October 2017. https://www.cites.org/eng/app/appendices.php [Accessed 02 December 2020].
CTAHR (College of Tropical Agriculture and Human Relations, University of Hawaii). 2020. Hawaiian Native Plant Propagation Database. Hibiscus brackenridgei. https://www.ctahr.hawaii.edu/hawnprop/plants/hib-brac.htm [Accessed 03 December 2020].
DOFAW (Division of Forestry and Wildlife, State of Hawaii). 2020. Threatened & Endangered Plants of Hawaii. https://dlnr.hawaii.gov/dofaw/rules/endangered-plants/ [Accessed 20 December 2020].
Fortini L, Price J, Jacobi J, Vorsino A, Burgett J, Brinck K, Amidon F, Miller S, Gon II S, Koob, G, Paxton E. 2013. A landscape-based assessment of climate change vulnerability for all native Hawaiian plants. Technical report HCSU-044. Hawaii Cooperative Studies Unit, University of Hawaii at Hilo, Hawaii.
FWS (U.S. Fish and Wildlife Service). 1999. Recovery Plan for Multi-Island Plants. U.S.Fish and Wildlife Service, Portland, Oregon. 206pages+appendices. https://ecos.fws.gov/docs/recovery_plan/990710.pdf
FWS (U.S. Fish and Wildlife Service). 1999. Recovery Plan for Multi-Island Plants. U.S. Fish and Wildlife Service, Portland, OR.
FWS (U.S. Fish and Wildlife Service). 2002. Addendum to the Recovery Plan for the Multi-Island Plants. Portland, OR.
FWS (U.S. Fish and Wildlife Service). 2013. 5 Year Review Hibiscus brackenridgei.
FWS (U.S. Fish and Wildlife Service). 2020. ECOS Environmental Conservation Online System. Species Profile (=Native yellow hibiscus) ma`o hau hele (Hibiscus brackenridgei). https://ecos.fws.gov/ecp0/profile/speciesProfile?spcode=Q1XE
Global Invasive Species Database (GISD). 2020. http://www.iucngisd.org/gisd/search.php [Accessed 03 December 2020].
Handy ESC, Handy EG, Pukui MK. 1991. Native Planters in Old Hawaii: their life, lore, and environment. Bishop Museum Press, Honolulu. Cited in UH 2009.
Heu RA, Nagamine WT, Kumashiro BR, and Thomas M. Watanabe TM. 2004. Giant Whitefly Aleurodicus dugesii Cockerell (Homoptera: Aleyrodidae). State of Hawaii. Department of Agriculture New Pest Advisory. No. 02-04, Updated June 2004 . Giant Whitefly Aleurodicus dugesii Cockerell. http://hdoa.hawaii.gov/pi/files/2013/01/npa02-04-giantwf.pdf
HWPRA (Hawaii-Pacific Weed Risk Assessment). 2020. ttps://sites.google.com/site/weedriskassessment/home . [Accessed 03 December 2020].
Keir, M. 2018a. Hibiscus brackenridgei subsp. molokaiana. The IUCN Red List of Threatened Species 2018: e.T80091009A80091047. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T80091009A80091047.en. Downloaded on 03 December 2020.
Keir, M. 2018. Hibiscus brackenridgei. The IUCN Red List of Threatened Species 2018: e.T62743A78757481. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T62743A78757481.en. Downloaded on 03 December 2020.
Lyon K. 2020. Hawaii Master Gardener Program. Chinese Rose Beetle. https://www.ctahr.hawaii.edu/uhmg/FAQ/faq-chinese-rosebeetle.asp [Accessed 03 December 2020].
Ness J, Bronstein J. 2004. The Effects of Invasive Ants on Prospective Ant Mutualists. Biological Invasions 6, 445–461 (2004). https://doi.org/10.1023/B:BINV.0000041556.88920.dd
NTBG (National Tropical Botanical Garden. 2020. Meet the Plants. Hibiscus brackenridgei subsp. brackenridgei. https://ntbg.org/database/plants/detail/hibiscus-brackenridgei-ssp-brackenridgei [Accessed 20 December 2020].
UH (University of Hawaii). 2009. Native Plants Hawaii. Hibiscus brackenridgei subsp. brackenridgei. http://nativeplants.hawaii.edu/plant/view/Hibiscus_brackenridgei_brackenridgei [Accessed 03 December 2020].
Wagner WL, Herbst DR, Sohmer SH. 1999. Manual of the flowering plants of Hawai’i (Revised ed.). Honolulu, Hawaii: University of Hawaii Press. ISBN978-0-8248-2166-1. Cited in NTBG 2020.
Page last updated September 29, 2022.