Hibiscus clayi is a perennial a flowering plant of the mallow family Malvaceae. It has several common names such as red Kauai rosemallow, Clay’s hibiscus or Kokiʻo ʻula (Hawaiian name). This hibiscus is an endemic shrub or small tree with bright red flowers, normally similar to H. kokio, and found in nature on Kauai in dry forests. It is listed as endangered hibiscus species by USFWS. The species name clayi honors to Horace F. Clay, a horticulturalist of Hawaii .
Description Hibiscus clayi is a shrub reaching height up to 4–8 meters.  Leaves of this hibiscus are shiny, medium green, smooth-edged or slightly toothed on the tip. Normally Single flowers are borne at the ends of the branches. This shrub shows bright or dark red flower and they bloom all year around. Flower of Hibiscus clayi generally similar to Hibiscus kokio .
This hibiscus species is endemic to Hawaii. It can be found in nature only in the dry
forest of Nounou Mountains in the eastern Kauaʻi, at an altitude of 50– 600 metres above sea level .
“Hibiscus clayi” (http://plants.usda.gov/java/profile?symbol=HICL). Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 14 April 2017.
“Hibiscus clayi” (https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?id=320431). Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA).
Retrieved 14 April 2017.
Native Plants Hawaii (http://nativeplants.hawaii.edu/plant/view/Hibiscus_clayi)
Lawton, Barbara Perry. Hibiscus: Hardy and Tropical Plants for the Garden (2004). (https://books.google.com/books?id
=VSEbamKS5uQC). Timber Press. p. 36. ISBN 978-0-88192-654-5.