What do Fiji, Australia, New Zealand, New Caledonia, Borneo, Australia and Hawaii have in common? This year several members of the Hawaii Chapter of the International Palm Society are about to find out. The society is having its 2016 biennial conference and tours in Singapore, Borneo and tropical northern Australia. Members will be not only meeting palm growers and enthusiasts, but will be collecting new palm species for Hawaiian gardens. The conference and field study will start June 12 in Sarawak, Borneo, and conclude with travel to far north Darwin, Australia, via Singapore. For details on the post Singapore tour to Darwin, the conference, IPS membership and other information, check out the IPS website at palms.org or email at info@palms.org.
What do Fiji, Australia, New Zealand, New Caledonia, Borneo, Australia and Hawaii have in common? This year several members of the Hawaii Chapter of the International Palm Society are about to find out. The society is having its 2016 biennial conference and tours in Singapore, Borneo and tropical northern Australia. Members will be not only meeting palm growers and enthusiasts, but will be collecting new palm species for Hawaiian gardens. The conference and field study will start June 12 in Sarawak, Borneo, and conclude with travel to far north Darwin, Australia, via Singapore. For details on the post Singapore tour to Darwin, the conference, IPS membership and other information, check out the IPS website at palms.org or email at info@palms.org.
Australia, Borneo, New Caledonia and perhaps islands like New Zealand and the Fiji group are thought to be part of the great continent known as Gondwana and hold some of the most ancient species of plants and animals known today. Surprisingly, even though Hawaii is about the youngest real estate around, the ancient species thus far introduced prove to be very hardy. Many are found to be extremely tolerant of extremes like wet and dry.
In the drier parts of our island, water-wise gardening starts with planting drought tolerant plants. Many palms fit this bill. Along with Hawaiian native plants, they can help us cut our water bill. For example, we may use our native Pritchardia, or loulu, palms but also use the two species, Pritchardia thurstonii and Pritchardia pacifica that are much easier to grow in difficult situations. In fact, P. thurstonii grows in profusion on small coral islets of the Lau group to the east of the larger Fiji Islands. At one time, these palms were much more common but the introduction of seed-eating rats severely limited their range.
It seems that all life has cycles. Ideas, attitudes and philosophies have cycles, as well. We shift from conservative to liberal and back. Clothing styles cycle as well. Even landscape design and plant popularity have cycles. Often, these swings of the pendulum hit an extreme before a movement back in the other direction. In plant use, we are swinging toward using local, native plants, and a few landscape designers are using only native plants. This is exciting since native plants have been ignored for a long time. It is important to protect and use our native plants in the landscape and at the same time be on the lookout for rare, beautiful and possibly endangered plants such as those from lands south of the equator to enhance our local landscapes. Some of these can grow where nothing else will.
Hawaii landscapes are well-known for their varied and unusual plant life. Many of these plants have been introduced from the West Indies, South America and Africa. But, few plants have adapted themselves so well as those from the South Pacific to Australia and the East Indies.
Australia is a vast and ancient continent. In some respects, it is the closest to the fabled “lost continent” where the ancestors of the dinosaur’s era still roam. It is a fact that this isolated land mass still contains some life forms that became extinct on other continents eons ago. It is not surprising that many plants from Australia adapt well to the Hawaiian Islands. With every climactic zone imaginable in Australia, plus an extremely long period of evolution, there are hundreds of species we can grow here.
Take for example the paperbark tree, Melaleuca leucodendron. It has long been used here as windbreaks. It, like the eucalyptus is closely related to our native ohia. Our native honeycreepers actually feed on the necter of these trees like they do the ohia. I don’t usually recommend the paperbark because it is so common and the flower smell is reminiscent of cooking mashed potatoes. However, there are scores of other species, some with lavender, pink, yellow or red flowers. They vary from bushes to tall trees. My favorite, Callistemon viminalis, has the form of a weeping willow with red bottlebrush like flowers.
In some tropical countries, paperbark is planted for reforestation purposes since it has some commercial use. The common paperback is well behaved in Hawaii, but in the Florida Everglades, it has done too well. This is because of the draining and burning of that region. This created an ecological vacuum that the trees found ideal. Now, instead of sawgrass, some areas of the Everglades are forested with paperbark.
The colorful bottlebrushes include the genera Callistemon and Melaleuca. Dozens of species are available in Australian nurseries, varying from small evergreen shrubs to large trees. Their flowers are made up of clusters of stems that look like the common kitchen bottle cleaner. Flowers vary from white and yellow to pink and red. Flowers are followed by woody seed capsules that look like beads pressed into the stem.
Advantages of the bottlebrushes are their insect and disease resistance, their tolerance of drought and wet conditions, and their overall attractive appearance. Some species like the weeping bottlebrush, Callistemon viminalis, bloom most of the year, and are also a source of nectar for our native honeycreepers.
Another Australian tree we take for granted in our Hawaiian landscape is the Casuarina or Australian pine. Named after the Cassowary bird, this primitive tree is not a pine at all. Our most common species, Casuarina equisitifolia, is extremely salt-tolerant and grows all along our beaches. One of its main advantages is that it protects other more tender plants from the strong salt-laden winds. Again, there are many interesting species. My favorite actually comes from the island of New Guinea. It is Casuarina papuana, with a broad weeping habit. In the garden, it usually grows to about 20 feet.
In Hawaiian gardens, you will find such common Australians as the Queensland umbrella tree, Brassaia actinophylla, macadamia nut tree, silk oak, banksias, acacias, Australian fire wheel (Stenocarupus) and Australian flame tree (Brachychiton). The palm so common to the windward sides of our island is the Alexandra palm, or Archontophoenix alexandrae. Another Achontophoenix is the king palm that is more robust and adapted to elevations up to 5,000 feet. Many Australian Livistona palm species and cycads have been introduced as well.
Although we have a number of Australian immigrants in our gardens, we have barely scratched the surface when it comes to the potential. There are more than 700 species of eucalyptus, 200 species of grevillea, 100 species of bottlebrushes (Callistemon and Melaleuca) and 500 species of acacia. There are also more than 50 species of palms.
Many of these unusual and interesting plants may find homes in Hawaii, especially as we begin to landscape in areas like South Kohala, Ka‘u, west Molokai, Lanai and even Kahoolawe where original vegetation has been destroyed and conditions due to climate change are hostile.
Even though New Caledonia, Borneo and other islands to the south are thought to be once connected to Australia, it must have been many millions of years ago. So little is known about plant species there that palm taxonomists will be exploring for species not yet found in Hawaii. The foxtail palm, common in landscapes today, was thought to be extinct for years. Recently rediscovered, it has become one of our most popular palms. Another that has been introduced and shows great promise is the Chambeyronia macrocarpa from New Caledonia. After this conference, it is assured that many more fantastic palms will follow.