Hibiscus roetae

Common Names:
St. John's Hibiscus
St. John's Rosemallow
Koki'o
Koki'o 'ula
Koki'o 'ula'ula
Maku

Classification:
Kingdom: Plantae-Plants
Subkingdom: Tracheobionta-Vascular plants
Superdivision: Spermatophyta-Seed plants
Division: Magnoliophyta-Flowering plants
Class: Magnoliopsida-Dicotyledons
Subclass: Dilleniidae
Order: Malvales
Family: Malvaceae - Mallow family
Genus: Hibiscus L.- Rosemallow
Species: Hibiscus kokio Hbd. ex Wawra -Red rosemallow
Subspecies: Hibiscus kokio Hbd. ex Wawra subsp.saintjohnianus (Roe) D.Bates - St.John's Rosemallow

(USDA, NRCS. 2006. The PLANTS Database, 7 June 2007 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.)
(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 leaves are oblong in shape, are 3-10 x 1.5-6.0 cm, as with many members of the Mallow family, 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 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.

This 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 stjohnianus 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.)

There are approximately 10 extant populations containing several thousand plants.

(Wood.K, pers.comm. 2000).

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.)


** The information provided above is not intended to be used as a guide for treatment of medical conditions using plants.

Threatened and Endangered Plants of Hawaii. Accessed on-line on 3 August 2007 http://www.state.hi.us/dlnr/dofaw/pubs/TEplant.html)

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 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 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.)

It is not known if Hau is native to Hawai‘i 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. L?`au Hawii`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.)