Hibiscus kokio subspecies saintjohnianus (Koki'o 'ula in Hawaiian) grows as either a shrub or a small tree growing from 3 to 7 m in height. The leaves are oblong in shape, are 3-10 x 1.5-6.0 cm. As with many members of the Mallow family (Malvaceae), the underside of the leaf is covered with stiff branched hairs that make the leaves rough to the touch. The solitary flowers develop near the end of the branches and as with all Hibiscus flowers are very striking because of their size and their form. All Hibiscus have a series of small bracts on the outside of the flower that are attached to the tubular calyx, which surrounds the base of the petals. The bracts appear as a star spreading out beneath the green calyx that contrasts strikingly with the orange or yellow petals. The petals of these flowers are 4.5-7 cm long and they spread out to reveal the stamens (pollen-producing structures) that are fused at the base into a single column before separating into individual yellow stamens towards the top. At the very tip of the column are five hairy stigma lobes onto which the pollen falls in order to fertilize the ovules. The fruit of Koki'o 'ula is a dry, brown capsule that is 1.6-1.8 cm long. This capsule and splits along its length when mature to release many dark brown seeds that are kidney-shaped and are 3-5 mm long. The two Hawaiian subspecies are distinguishable based on several characteristics: Hibiscus kokio subspecies kokio has densely hairy leaves and stems, long bracts on the calyx, and red flowers, whereas Hibiscus kokio subspecies saintjohnianus has fewer hairs on the leaves and stems, short bracts on the calyx, and orange, orange-red, or yellow flowers. (Wagner, W. L., Herbst, D. R., and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawai'i. Revised Edition. Volume 1.)(Bishop Museum Special Publication 97. University of Hawai'i Press, Bishop Museum Press, Honolulu, Hawai'i.)
The juice from the leaves and the buds of various native Hibiscus species is used to treat constipation, acting as a gentle laxative. The flowers reportedly serve as an astringent, while the root contains mucilage, which is used for its soothing effect on the respiratory and digestive tracts. (Kaaiakamanu, D.M. and J.K. Akina. 1922. Hawaiian Herbs of Medicinal Value.)
Koki'o 'ula (Hibiscus kokio subspecies saintjohnianus) is not extensively used in cultivation but cultivars known as Haena Red and Velvet Sunset are available. This subspecies is densely branched and provides a good accent plant in native gardens. Hibiscus kokio subspecies kokio can be found more frequently in cultivation and is known as Hakalau Red, Kipu Red, and Oahu Red. This subspecies forms a narrow shrub that is not densely branched. The tolerance of Koki'o 'ula to dry conditions means that it is a good native species for planting in dry, leeward regions of the Hawaiian Islands that do not require extensive additional watering. Koki'o 'ula is also used for root stock for grafting of other Hibiscus cultivars. (Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants cultivated in the Hawaiian Islands and other tropical places. Bishop Museum Press, Honolulu, Hawai'i.) (Wagner, W. L., Herbst, D. R., and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawai'i. Revised Edition. Volume 1.)(Bishop Museum Special Publication 97. University of Hawai'i Press, Bishop Museum Press, Honolulu, Hawai'i.)
The bark of a common species in Hawai'i, Hibiscus tiliaceous, known by the common name Hau, is widespread in coastal vegetation throughout Hawai'i. It is not known if Hau is native to Hawai'ii and was found here prior to human contact or if it was introduced by the early Polynesian settlers who used the fibers from the fibers of this plant for cordage and the light wood in the construction of outrigger structures. (Abbott, I A. 1992. La`au Hawai`i: Traditional Hawaiian Uses of Plants. Bishop Museum Press, Honolulu, Hawai`i.) (Wagner, W. L., Herbst, D. R., and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawai'i. Revised Edition. Volume 1.)(Bishop Museum Special Publication 97. University of Hawai'i Press, Bishop Museum Press, Honolulu, Hawai'i.)
Koki'o 'ula (Hibiscus kokio subspecies saintjohnianus) is endemic to the island of Kauai in the Hawaiian Islands. It is restricted to the northwestern portion of the island and is found between 150 and 890 m in elevation. There are approximately 10 extant populations containing several thousand plants. (Wood.K, pers.comm. 2000).
The name of this species commemorates one of Hawai'i's most well known botanists, Harold St. John. (Kepler, A.K. 1995. Maui Floral Splendor.)
Hibiscus kokio is considered as a species of concern by the Endangered Species Act. (USFWS, DLNR. Threatened and Endangered Plants of Hawaii. Accessed on-line on 3 August 2007 http://www.state.hi.us/dlnr/dofaw/pubs/TEplant.html)
We currently have 36 herbarium specimens for Hibiscus kokio subsp. saintjohnianus in our collection. Click on any specimen below to view the herbarium sheet data.
