HAWAI'I GARDENS
Botanical garden saves rare Hawaiian hibiscus
By Heidi Bornhorst
Dear Heidi: What is so great about botanical gardens? Aren't they just pretty parks with old trees?
— John Nekoba, Waipahu
Dear John: Botanical gardens are vital and important. While people are busy earning a living and raising their keiki and doing other things, our forests and native flora and fauna are in deep trouble. Many species that would have gone extinct in the wild are kept alive today thanks to the help and diligence of botanical gardens.
Waimea Arboretum, for instance, has a long track record of perpetuating the rarest of the native Hawaiian plants as well as other wonderful and endangered plants from the tropics. The arboretum takes extraordinary steps to perpetuate these plants for our future generations.
Waimea is the garden that kept the variety of hibiscus called kokia, for one, from extinction.
Kokia is one of two surviving genera of hibiscus endemic to Hawai'i. (Hibiscadelphus, or hau kuahiwi is the other; we'll discuss it in a future column.)
Once there were many species of kokia on all the islands. They have red or orange flowers that are somewhat curved and tubular. Scientists tell us that these are highly evolved hibiscus relatives, designed for being fed upon and thus pollinated by the once-abundant native birds.
Today, sadly, there are only three species of Kokia still in existence. They are: Kokia kauaiensis from Kaua'i, K. drynarioides from the Big Island, and K. cookei from Moloka'i. K. cookei is the rarest. It is extinct in the wild.
Moloka'i was once down to one K. cookei plant in the yard of the Cooke family. Waimea Arboretum experts took seeds and cuttings from the one lonely plant and tried all kinds of ways to grow this rare and wonderful plant. The seeds wouldn't grow, and neither did the cuttings. Finally, they tried an old technique that takes a bit of expertise: grafting. That finally worked, and they got a couple of K. cookei growing on the rootstocks of the other more vigorous species.
Then, tragedy struck! The Cooke home on Moloka'i burned, and the K. cookei burned up too! Auwe!
Fortunately, the grafted K. cookei still was thriving at Waimea. The arboretum has shared plants with other gardens. Director David Orr and dedicated plant propagators such as volunteers Erin Purple and Franny Okamoto continue to care for the kokia and myriad other rare plants as they try to figure how to grow more.
Tissue culture, micro propagation and in-vitro culture all look like promising tools for the propagation and perpetuation of kokia and other rare plants from Hawai'i and around the world.
