Native Hawaiian Plants Flourish in Westwood

Nobody can remember who first proposed cultivating a special collection of native Hawaiian plants at UCLA's Mildred E. Mathias Botanical Garden, so now we have an unsung hero. With the opening of phase two of our Hawaiian collection on May 16--at a ribbon-cutting ceremony attended by forty-five staff, volunteers, and friends--our display now high-lights species in about forty genera. But counting plants and racking up numbers is not our principal goal. Instead, we at MEMBG have two functions in mind for the Hawaiian section: first, we want it to serve as a refugium, or safe haven, for plant species that are threatened by extinction in their native land; and, second, we want to use the section to teach the public and our students about plant evolution.

The current flora of the Hawaiian Islands includes nearly 2,000 species of flowering plants and lower vascular plants (ferns and club mosses, for example). Of these, about 60 percent are native or indigenous species (that is, species not introduced by humans). Moreover, approximately 90 percent of the indigenous species now living on the Hawaiian Islands are endemics, meaning that they occur there and nowhere else on earth. More than thirty endemic genera occur among the Hawaiian flora--quite a remarkable number for an area that is only slightly larger than Connecticut. You can find pictures of many of these plants online, at the University of Hawaii Web site (http://www.botany.hawaii.edu). In addition, the angiosperms of the flora are professionally described in the Manual of the Flowering Plants of Hawai'i written by W. L. Wagner, D. R. Herbst, and S. H. Sohmer (University of Hawaii Press, 1990).

Perhaps surprisingly, Hawaiian native plants are not what the typical tourist sees or hears about when visiting the islands. Well-known species of orchids, plumeria, pineapple, bananas, ginger, and macadamia nuts all were introduced to the islands after Europeans settled there.

At MEMBG we are primarily interested in cultivating perennials, which can be maintained year after year without needing to be reseeded. For us, these species may not be the rare ones, but they are fascinating to lovers of tropical and subtropical plants. Some of them hold potential as horticultural species for Southern California, and, for that reason, our trials may yield some new plants for local gardens.

One of the trees that has done exceedingly well is called koa (Acacia koa), the wood of which is used for making ukuleles and fine furniture. Koa is a phyllodineous acacia (like many in Australia), which has phyllodes, modified leaves in which the blade is absent and the petiole has become the flattened photosynthetic organ. Our specimens of koa are very useful for educational purposes, because they also form juvenile foliage consisting of twice pinnately compound leaves with very small leaflets, giving instructors an opportunity to talk about the fundamentals of leaf development.

Other trees with potential for local horticulture belong to the only indigenous genus of palms, Pritchardia. This lineage is endemic to tropical Pacific islands and includes nineteen of twenty-five species endemic to the Hawaiian Islands. We are attempting to grow several of these at MEMBG.

Some MEMBG favorites are the many species of Hawaiian Malvaceae (mallow family), in particular the unusual and showy native species of Hibiscus. Another popular plant, which has been grown for many years in Westwood, is Wilkesia gymnoxiphium, called iliau, a close relative of the Hawaiian silversword, Argyroxiphium sandwicense. The wilkesia is a short "rosette tree" that has an unbranched woody stalk adorned at the top with monocotyledon-like, strap-shaped leaves. In fact, this species is a member of the sunflower family (Asteraceae) and not a monocotyledon. The major drawback of growing wilkesia is that after it flowers--a spectacular event--the entire plant dies, so new plants must be grown from seed.

Phase one of our special Hawaiian collection was sponsored in the mid-1980s by Kei Nakai of Hawthorne Nursery in El Segundo. Plans for phase two began in 1993, and MEMBG received funding from the Elvenia J. Slossen Foundation for constructing the new section to accommodate different types of plant habitats, including a bog and a wall of volcanic rocks kept wet by misters. Now, congratulations are in order for garden manager Rand Plewak and his hardworking crew for the combined thousands of hours of labor and creativity that they invested in the project. Rand certainly earned the honor of cutting the ribbon at the dedication ceremony.

Labels on the new plantings will be appearing this summer, as the plants root and adjust to life on the UCLA campus. After the collection is firmly established, we will produce a guide booklet for the display. If any of our readers are interested in helping to sponsor some of these endeavors, please call the garden.

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