PlantFiles: Kenaf, Brown Indian Hemp
Hibiscus cannabinus

I have grown this plant. Hibisus cannabinus is often confused with Hibiscus radiatus so I have completed research in an attempt to find distinguishing characteristics that differientiate the 2 plants. Hibiscus radiatus is an allotetraploid of Hibiscus cannabinus and perhaps Hibiscus surratensis. The term allotetraploid refers to an organism that contains four complete copies of the genome, but two (and rarely, one) of the copies are from a different species than the other two copies. H. cannabinus leaves and calyx lobes are glandular and has epicalyx (a series of bracts subtending and resembling a calyx) segments attached to the calyx which are not characteristics of H. radiata. H. cannabinus has an elongate nectary gland at the base of the lower leaf midrib and on the midvein of each calyx lobe as well as a whitish tomentellum on the calyx which H. radiatus does not have. H. radiatus has a tooth-like appendage below the apex on the inner surface of the epicalyx bractlets which is not present on H. cannbinus.. H. cannabinus blooms are 4 to 6 inches across; whereas, H. radiatus has 3 to 3.5 inch across blooms. In many references, H. radiatus is said to grow a little over 3 feet tall; however, in cultivation, it can grow 6 to 8 feet tall. In cultivation H. cannabinus can grow 12 to 15 feet tall. Both can have cerise-pink (mauve-pink, burgandy-pink) that have a dark center. H. radiatus var. flore purpureo is one with rose-purple petals. I have grown H. cannabinus. Judging from photos that I know correctly identify H. radiatus, the leaflets of H. radiatus appear to broaden more in their middle sections as compared to H. cannabinus leaflets. The above information has been gathered from various scientific resources on the internet. Many websites I believe have misidentified H. cannabinus as H. radiata and vice-a-versa. I do not have any books which include detailed descriptions of H. radiatus nor H. cannabinus. Please let me know if any of the above information is incorrect and please add information that may be of assistance with the identification of H. radiata and H. cannabinus.

Note: H. cannabinus and H. radiatus are deer resistant due to the tiny thorns on the undersides of their leaves and along their stems.