It was discovered in 1991 and described as a new species in 1995.[3] Only four individuals were found at that time; three of those were crushed by a boulder and died between 1995 and 1998, and the last was found dead in 2011. Pollen was found to be inviable, no fruit set was ever observed and all attempts at propagation, including by cross-pollination with H. distans, failed.[6] It was later assessed as extinct by the International Union for Conservation of Nature in 2016,[1] but three individuals were rediscovered in 2019 by the National Tropical Botanical Garden.[7] The plants were growing out of a steep cliff and were found using drones.[8]
^ abLorence, David H.; Wagner, Warren L. (1995). "Another New, Nearly Extinct Species of Hibiscadelphus (Malvaceae) from the Hawaiian Islands". Novon. 5: 183–187. doi:10.2307/3392243. JSTOR3392243. Retrieved 2021-03-11. Four individuals of a new species of Hibiscadelphus (Malvaceae: Hibisceae) have been discovered on Kaua'i, the oldest of the major Hawaiian Islands. Hibiscadelphus woodii is described and illustrated, and its status and basal relationship within the genus are discussed. The imperiled status of the other six species is review, and a key to the genus is given.
^USDA, NRCS (n.d.). "Hibiscadelphus woodii". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 14 May 2015.
^"Hibiscadelphus woodii". CPC National Collection Plant Profiles. Center for Plant Conservation. 22 July 2008. Archived from the original on 30 October 2010. Retrieved 14 November 2009.