Kawaihae hibiscadelphus

Hibiscadelphus bombycinus was a tree or shrub, growing up to about 4.5 meters (15 feet) tall. The leaves were kidney-shaped or circular, stellate pubsecent (having star-shaped hairs) on both sides but especially below. Leaves had five poorly defined lobes with slightly wavy margins and rounded tips which overlapped at the base of the leaf. Petioles were hairy and 4.2 to 5.2 centimeters long. Pedicels of 2.1 to 3 centimeters in length bore single flowers with 9 millimeter long strap-shaped involucral bracts. The flower's calyx was six-lobed, cup-shaped, and stellate pubescent. The petals were 3.4 centimeters long, covered in dense stellate hairs, slightly curved, and barely opened at all, as is the case with other Hibiscadelphus species. Capsules were woody, with dense yellowish stellate hairs covering the exterior surface, and were either circular and 2.9 centimeters tall or egg-shaped and 3.2 centimeters tall.

Nothing is known about Hibiscadelphus bombycinus's habitat and ecology. The holotype was collected on the leeward slopes of Kohala, and it likely occurred in moist to mesic forests.