Hibiscadelphus bombycinus (Kawaihae Hibiscadelphus)

[Melanie]

1. Hibiscadelphus bombycinus C. Forbes (end, Ex)

Presumably small trees. Leaf blades broadly oblong-ovate, 3-8.5 cm long, upper surface sparsely pubescent, lower surface densely pubescent, especially in axils of major veins, 3-angled or 5-angled or lobed, margins irregularly crenate, base deeply cordate with a closed sinus, petioles 1-5 cm long. Flowers solitary, pedicels ca. 2 cm long in flower, up to 4 cm long in fruit; involucral bracts 6, connate slightly at base, linear-oblong to spatulate, 9-10 mm long, 1-5.3 mm wide; calyx tubular-campanulate, ca. 1.2 cm long, apparently deciduous; corolla moderately curved, ca. 3.3 cm long. Capsules woody, slightly obovoid, apiculate, 2.5-3 cm long, mesocarp strongly developed, reticulate, endocarp segments 10. Seeds ca. 6 mm long, yellowish lanate. Apparently now extinct, collected only once, before 1868, probably in mesic forest, at Kawaihae, Hawai'i (Forbes, 1920; Degener, 1937c).

[Melanie]

4, Leaves usually 8 cm wide or less;
found originally in the wild on
western slopes of Kohala Mountains
above Kawaihae, but now beliwed to be
extinct . . . . . . . . . . . . . . . . . H. bombycinus

[Melanie]

source: The Doomsday Book of Animals

[Melanie]

Prior to the time of Rock’s collections in the early 1900’s another species of Hibiscadelphus had been discovered unknowingly by William Hillebrand. It was collected from the arid slopes above Kawaihae, Hawai’I, sometime between 1851 and 1871. Hilebrand also recognized the similarity of his specimen to Hibiscus and labelled his specimens “Hibiscus section bombycinus” However, Hillebrand never published his name and the specimens eventually wound up in the herbarium of the Bernice P. Bishop Museum, Honolulu. There, Charles N. Forbes (1920) recognized the specimens for what they were and he described the Kawaihae species as Hibiscadelphus bombycinus. Forbes separated the new species from its closely allied congener H. hualalaiensis on the basis of having strap-shaped (broader) involucral bracts and smaller leaves.

No other collections of H. bombycinus have ever been made, and because of the destruction of much of the native vegetation in the region around Kawaihae by cattle grazing and wildfire the species may be extinct.

[Peter]

Source for the two first posts by Melanie: www.hibiscus.org.au/part2.htm
(Wagner, W., Herbst, D. and Sohmer, S. 1990. Manual of the flowering plants of Hawaii. University of Hawaii Press, Bishop Museum Press, Honolulu.)

Author of the image in the Doomsday Book of Animals: Pat Harby.

And source of the fourth post by Melanie: www.botany.hawaii.edu/faculty/duffy/techr/034.pdf

[anotherspecialist]

Range Description: It was thought to occur in rainforest at Kawaihae on Hawaii. The genus is endemic to the Hawaiian Islands and is known from species which are either Extinct or Critically Endangered.

Population: Collected just once before 1868, the species is now presumed extinct.

www.iucnredlist.org/search/details.php/30774/all

[koeiyabe]

plants.jstor.org/search?filter=name&so=ps_group_by_genus_species+asc&Query=Hibiscadelphus+bombycinus

[koeiyabe]

explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.148825/Hibiscadelphus_bombycinus

Common name: Kawaihae Hibiscadelphus