Along with the chance to experience some of the most striking flora in the world, a visit to the San Diego Zoo’s Hawaiian gardens contains more horticultural surprises than you can shake a grass skirt at. Amid the lush, tropical greenery that Hawaii is known for lies a botanical bombshell: most palm trees, even the popular coconut and date palms, are not native to the “Islands of Aloha.” They’re “canoe plants,” or transplants brought over by either early Polynesian settlers or the many later cultures that would arrive and make Hawaii their home. You can encounter native palms (also known as loula palms), members of the Pritchardia group, among the many horticultural wonders in the Zoo’s three Hawaiian gardens.
The oldest of the Zoo’s Hawaiian gardens, planted in 2001, is on the walk approaching the Tasmanian devils. The other two grace spots on Center Street: one right under the wall slope adjacent to Sydney’s Grill, and the other on the sloped hillside across from the grizzly bears. A visit to the Hawaiian gardens reveals treasures like the false ohe Polyscias racemosa, or the pokalakala Munroidendron racemosum, an enigmatic endangered species from Kauai that offers a nice canopy for shade. The Zoo’s collection also includes the alula, also called vulcan palm or cabbage on a stick Brighamia insignis, which is neither a plant owned by Mr. Spock nor a suitable source for coleslaw. This critically endangered, short-lived perennial species is extinct in the wild, save for a single sea cliff on Kauai. It’s the dedication to saving such rare specimens that drove the effort to make part of the Zoo a little Hawaiian paradise.
“Our Hawaiian gardens started with a single koa tree near Australian Outback,” says Michael Letzring, the Zoo’s senior plant propagator. “The Hawaiian Islands have been called the endangered species capital of the world, with more endangered species per square mile than any place on Earth. To save the last remaining plants from extinction, many steps must be taken. The San Diego Zoo has developed a living exhibit showcasing some Hawaiian plants in hopes that people will become aware of the treasure we have in the flora of the Hawaiian Islands.”
But what won’t you find? Plumeria! Despite its use in leis and its image on everything from Hawaiian jewelry to the patterns on luau wear, this beautiful blossom hails from other Pacific Islands, Mexico, and Central America—not Hawaii. Some species of another floral favorite—the hibiscus—are native to Hawaii, and the yellow variety is the official state flower. The white ones, which are the only scented type, are not. A look at Hawaii’s history offers clues as to how some “Hawaiian” imposters became rooted in people’s minds as native.
Hawaii is the most remote archipelago in the world. Because of this, over the course of millions of years plants have evolved differently than in, for example, Africa or North America. Ocean currents, as well as birds, carried seeds from all points around the Pacific Ocean and distributed them onto the islands. These seeds colonized and then morphed into new species more suitable for their new land. Unfortunately, since the arrival of humans, native plants have been on the decline.
At the San Diego Zoo, we realize we have the ability to help save and preserve many species that are threatened in their native habitats. “We have plants here that occur nowhere else in the world outside Hawaii,” says Lesley Randall, horticulture supervisor at the Zoo. “We are able to make it all work as an ecosystem. If the difference in humidity is an issue, we keep the plant protected by shade.”
There are some species that we are unable to grow here in San Diego due to climate differences, but we are always adding new ones and growing species in our off-exhibit greenhouse. For us, it is a thrill to try to create an area in the Zoo that mimics the Hawaiian Islands, right down to the lava rocks! Come say Aloha to our own little corner of paradise.
Peggy Scott is an associate editor for San Diego Zoo Global. Read her previous blog, Babies ‘R’ Us: A Day in the ACC Nursery.