””’Hibiscadelphus wilderianus””’, also known as the ”’Maui hau kuahiwi”'<ref>{{PLANTS|id=HIWI|taxon=Hibiscadelphus wilderianus|accessdate=14 May 2015}}</ref>, is an [[extinct]] species of [[flowering plant]] in the family [[Malvaceae]] that was [[endemic]] to the island of [[Maui]] in [[Hawaii]].
””’Hibiscadelphus wilderianus””’, also known as the ”’Maui hau kuahiwi”'<ref>{{PLANTS|id=HIWI|taxon=Hibiscadelphus wilderianus|accessdate=14 May 2015}}</ref>, is an [[extinct]] species of [[flowering plant]] in the family [[Malvaceae]] that was [[endemic]] to the island of [[Maui]] in [[Hawaii]].
In 2019, American [[biotechnology]] company [[Ginkgo Bioworks]] recreated the scent of ”Hibiscadelphus wilderianus”<nowiki/>‘s flower for a commercial [[Aroma compound|fragrance]] line using [[DNA]] sequenced from the sole existing [[herbarium]] specimen.<ref>{{Cite web |title=Scent of Extinct Maui Mountain Hibiscus Revived by Science {{!}} Maui Now |url=https://mauinow.com/2019/02/19/scent-of-extinct-maui-mountain-hibiscus-revived-by-science/ |access-date=2025-08-12 |website={{!}} Scent of Extinct Maui Mountain Hibiscus Revived by Science}}</ref>
In 2019, American [[biotechnology]] company [[Ginkgo Bioworks]] recreated the scent of ”Hibiscadelphus wilderianus”’s flower for a commercial [[Aroma compound|fragrance]] line using [[DNA]] sequenced from the sole existing [[herbarium]] specimen.<ref>{{Cite web |title=Scent of Extinct Maui Mountain Hibiscus Revived by Science {{!}} Maui Now |url=https://mauinow.com/2019/02/19/scent-of-extinct-maui-mountain-hibiscus-revived-by-science/ |access-date=2025-08-12 |website={{!}} Scent of Extinct Maui Mountain Hibiscus Revived by Science}}</ref>
== Taxonomy ==
== Taxonomy ==
== Description ==
== Description ==
”Hibiscadelphus wilderianus” was a small [[tree]], growing to about 5 meters (16 feet) in height. The [[Leaf|leaves]] were [[Trichome|pubescent]] and rounded, with three lobes and five distinct palmately-arranged veins. It bore singular [[Flower|flowers]] with yellow [[Petal|petals]] on 4 centimeter (1.5 inch) long [[Peduncle (botany)|peduncles]], and produced oval-shaped, roughly-textured woody [[Capsule (fruit)|capsule]] fruits.<ref name=”:0″ />
”Hibiscadelphus wilderianus” was a small [[tree]], growing to about 5 meters (16 feet) in height. The [[Leaf|leaves]] were [[Trichome|pubescent]] and rounded, with three lobes and five distinct palmately-arranged veins. It bore singular [[]] with yellow [[]] on 4 centimeter (1.5 inch) long [[Peduncle (botany)|peduncles]], and produced oval-shaped, roughly-textured woody [[Capsule (fruit)|capsule]] fruits.<ref name=”:0″ />
== Distribution and Habitat ==
== Distribution and ==
”Hibiscadelphus wilderianus”<nowiki/>‘s type specimen was found at 800 meters (2,265 feet) elevation in the [[dry forest]] [[Lava field|lava fields]] of [[Auwahi Dryland Forest Restoration Project|Auwahi]] on the rocky, dry southern slopes of Mount [[Haleakalā]] on Maui. Being on the [[Windward and leeward|leeward]] side of Mount Haleakalā, this region is relatively arid, receiving only 20 to 60 inches of rainfall annually.<ref>{{Cite web |title=Park Archives: Haleakala National Park |url=https://npshistory.com/publications/hale/index.htm |access-date=2025-08-12 |website=npshistory.com}}</ref>
”Hibiscadelphus wilderianus”’s type specimen was found at 800 meters (2,265 feet) elevation in the [[dry forest]] [[lava ]] of [[Auwahi Dryland Forest Restoration Project|Auwahi]] on the rocky, dry southern slopes of Mount [[Haleakalā]] on Maui. Being on the [[Windward and leeward|leeward]] side of Mount Haleakalā, this region is relatively arid, receiving only 20 to 60 inches of rainfall annually.<ref>{{Cite web |title=Park Archives: Haleakala National Park |url=https://npshistory.com/publications/hale/index.htm |access-date=2025-08-12 |website=npshistory.com}}</ref>
==Extinction==
==Extinction==
The habitat of ”Hibiscadelphus wilderianus”, the dry forest lava fields on Haleakalā’s southern slope, has been severely [[Deforestation|deforested]] for use by [[Ranch|cattle ranchers]], and very few pockets of remnant native vegetation remain today. Remaining forest also faces substantial pressure from [[Wildfire|fire]], browsing and grazing by [[Introduced species|introduced]] [[Ungulate|ungulates]] (such as [[cattle]], [[Goat|goats]], and [[Feral pig|feral pigs]]), and invasion by introduced [[grasses]] and other plant species.
The habitat of ”Hibiscadelphus wilderianus”, the dry forest lava fields on Haleakalā’s southern slope, has been severely [[Deforestation|deforested]] for use by [[Ranch|cattle ranchers]], and very few pockets of remnant native vegetation remain today. Remaining forest also faces substantial pressure from [[Wildfire|fire]], browsing and grazing by [[Introduced species|introduced]] [[]] (such as [[cattle]], [[]], and [[ pig]]), and invasion by introduced [[grasses]] and other plant species.
”Hibiscadelphus wilderianus”<nowiki/>‘s flower morphology, like that of other ”[[Hibiscadelphus]]”, suggests that it would have relied upon the [[Hawaiian honeycreeper|Hawaiian honeycreepers]] for [[pollination]]. The loss of its primary [[Pollinator|pollinators]] caused by the decline and extinction of many species of Hawaiian honeycreepers, then, would have contributed to the declines and potential [[Coextinction|coextinctions]] of ”Hibiscadelphus” species, including ”Hibiscadelphus wilderianus”.<ref>{{Cite journal |last=Hobdy |first=Robert W. |date=30 April 1984 |title=A Re-evaluation of the Genus Hibiscadelphus (Malvaceae) and the Description of a New Species |url=https://hbs.bishopmuseum.org/pubs-online/pdf/op25-11.pdf |journal=Bishop Museum Occasional Papers |volume=XXV |issue=11}}</ref>
”Hibiscadelphus wilderianus”’s flower morphology, like that of other ”[[Hibiscadelphus]]”, suggests that it would have relied upon the [[Hawaiian honeycreeper]] for [[pollination]]. The loss of its primary [[]] caused by the decline and extinction of many species of Hawaiian honeycreepers, then, would have contributed to the declines and potential [[]] of ”Hibiscadelphus” species, including ”Hibiscadelphus wilderianus”.<ref>{{Cite journal |last=Hobdy |first=Robert W. |date=30 April 1984 |title=A Re-evaluation of the Genus Hibiscadelphus (Malvaceae) and the Description of a New Species |url=https://hbs.bishopmuseum.org/pubs-online/pdf/op25-11.pdf |journal=Bishop Museum Occasional Papers |volume=XXV |issue=11}}</ref>
The type specimen died within a few years of discovery. When it was revisited in 1912, it was covered in [[lichen]] (believed to have been ”[[Usnea|Usnea australis]]”) and in decline. Gerrit Wilder, for whom the plant was named, was able to collect some seed from the tree in 1912, and reportedly successfully raised a single seedling. However, Wilder believed that the area’s use for cattle ranching meant that the extinction of the species was inevitable.<ref name=”:1″ />
The type specimen died within a few years of discovery. When it was revisited in 1912, it was covered in [[lichen]] (believed to have been ”[[Usnea|Usnea australis]]”) and in decline. Gerrit Wilder, for whom the plant was named, was able to collect some seed from the tree in 1912, and reportedly successfully raised a single seedling. However, Wilder believed that the area’s use for cattle ranching meant that the extinction of the species was inevitable.<ref name=”:1″ />
Extinct species of flowering plant
Hibiscadelphus wilderianus, also known as the Maui hau kuahiwi[3], is an extinct species of flowering plant in the family Malvaceae that was endemic to the island of Maui in Hawaii.
In 2019, American biotechnology company Ginkgo Bioworks recreated the scent of Hibiscadelphus wilderianus‘s flower for a commercial fragrance line using DNA sequenced from the sole existing herbarium specimen.[4]
It was described in 1911 by Austrian-American botanist Joseph Rock, based on his discovery in 1910 of the type specimen, a single tree on the southern slope of Haleakalā. The species name, wilderianus, was given in honor of Rock’s friend Gerrit P. Wilder for his interest in growing and producing different varieties of Hibiscus.[5] Wilder also collected the first open flowers from the type specimen, which formed the basis for the scientific description.[6]
In 1973, L. Earl Bishop and Derral Herbst suggested that Hibiscadelphus wilderianus and Hibiscadelphus giffardianus may be variants of the same species due to their high morphological similarity. However, the status of the two species (being extinct and extinct in the wild, respectively) makes further study by comparing wild populations impossible.[7]
Hibiscadelphus wilderianus was a small tree, growing to about 5 meters (16 feet) in height. The leaves were pubescent and rounded, with three lobes and five distinct palmately-arranged veins. It bore singular flowers with yellow petals on 4 centimeter (1.5 inch) long peduncles, and produced oval-shaped, roughly-textured woody capsule fruits.[5]
Distribution and habitat
[edit]
Hibiscadelphus wilderianus‘s type specimen was found at 800 meters (2,265 feet) elevation in the dry forest lava fields of Auwahi on the rocky, dry southern slopes of Mount Haleakalā on Maui. Being on the leeward side of Mount Haleakalā, this region is relatively arid, receiving only 20 to 60 inches of rainfall annually.[8]
The habitat of Hibiscadelphus wilderianus, the dry forest lava fields on Haleakalā’s southern slope, has been severely deforested for use by cattle ranchers, and very few pockets of remnant native vegetation remain today. Remaining forest also faces substantial pressure from fire, browsing and grazing by introduced ungulates (such as cattle, goats, and feral pigs), and invasion by introduced grasses and other plant species.
Hibiscadelphus wilderianus‘s flower morphology, like that of other Hibiscadelphus, suggests that it would have relied upon the Hawaiian honeycreepers for pollination. The loss of its primary pollinators caused by the decline and extinction of many species of Hawaiian honeycreepers, then, would have contributed to the declines and potential coextinctions of Hibiscadelphus species, including Hibiscadelphus wilderianus.[9]
The type specimen died within a few years of discovery. When it was revisited in 1912, it was covered in lichen (believed to have been Usnea australis) and in decline. Gerrit Wilder, for whom the plant was named, was able to collect some seed from the tree in 1912, and reportedly successfully raised a single seedling. However, Wilder believed that the area’s use for cattle ranching meant that the extinction of the species was inevitable.[6]
Given the destruction of much of its natural habitat and the death around 1912 of the sole known tree, Hibiscadelphus wilderianus is presumed to be extinct.[1]
