Hawai'i Gardens
Elephant apple interesting but not really worth eating

By Heidi Bornhorst

An e-mail from Liz Dolan posed this question about a fruit and tree she's seen driving through town: "These are growing along Pali Highway on the way to town, just before the Waokanaka light, right side. From a distance they look like avocados (we thought so at first) but were told they are called elephant apples. What about 'em??"

Elephant apples are known scientifically as dillenia because they are in the Dilleniaceae family. Another common name is simpoh. There are about 60 species of dillenia, and their natural distribution is from Madagascar eastward to Australia.

Dillenia indica is native to southeast Asia. It has large, leathery leaves with distinct veins, and is a medium-sized tree. The flowers are large and white and really show up when they are in bloom. If the flower gets properly pollinated it will develop into fruit. The fruit is three to five inches across. It is sometimes eaten in India — they add it to curries — but it is said to not have much nutritional value for humans. There is a species from the Philippines with smaller fruit, about two inches across. It is eaten there.

Dillenia are growing in several of your city botanical gardens: a large tree is at Wahiawa Botanical Garden near the bromeliad display house; there is also a nice one, full of attractive and interesting fruit, on the tropical terrace at Foster Botanical Gardens.

We have some also in Kahua Kuou, the Indian and Sri Lankan section at Ho'omaluhia Botanical Gardens. That one is called Dillenia suffruticosa and it came from the Peradinya botanical garden in Sri Lanka, a very famous and historic garden. D. suffruticosa has very pretty yellow flowers that are about three inches wide and small pinkish fruit that are eaten by birds who then spread the seeds far and wide, nourished with their kukae. Now it is popping up everywhere around the original trees and becoming a weed.

We found out that D. suffruticosa is one of the most common plants in Malaysia, where it is called simpoh air. It forms dense thickets in secondary forests and in wet swampy areas. The fruits open up into a star-like shape and have seeds encased in a fleshy pink aril or bit of fruit. This is very attractive and 'ono to birds.

Some plants, in fact many, when brought into Hawai'i, go nuts and become weeds. This has happened with this pretty yellow-flowered one at Ho'omaluhia, and staff and volunteers are working hard to eliminate it before it really escapes into the native forests. If you would like to volunteer and help get rid of this pest, call Eileen at Ho'omaluhia, 233-7325. Four hundred acres is a lot of garden to manage with a small and dedicated crew. Volunteers are essential for this treasured facility.

This brings to mind an important point: We all need to be responsible as gardeners and prevent new weed escapees, as well as obnoxious frogs, insects, nematodes in soil and so on. Be careful what you plant and what you move from place to place.

Heidi Bornhorst is director of Honolulu's five botanical gardens.