Tropical Gardening: Our state tree: kukui or loulu?
If you are truly interested in conservation, then choose to protect one of our most unique plant species, the genus pritchardia. If you think that coconut palms, kukui, bananas, taro and ti are natives and seem to grow easily, then it is time to rethink. These plants are alien, non native species brought to Hawaii by the Polynesians as they migrated across southeast Asia and the Pacific Ocean.
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For example, our state tree, the kukui, originated in what is now Indonesia, it is believed. Our state tree probably should be the loulu palm genus because it is endemic. That is, it is found only in Hawaii. Of course there are exceptions to this. Two species are found in the south Pacific. The Hawaiian loulus actually evolved here and are found growing naturally only in Hawaii. At one time, there may have been many dozens of species, but with the introduction of the Polynesian rat and pig, many must have perished. Later introduction of grazing animals did further damage so that now there are only remnants of what must have been vast populations of the loulu.
The native loulu group or pritchardia palms are truly a vanishing species in Hawaii. Of some 26 species of pritchardias in the world, 24 are natives of Hawaii. The others are found in Fiji and the Tuamotos.
It is a shame that many of these species have declined in number to the point that they are almost extinct. It’s suspected that there may have been other species present on other Pacific islands, but have probably disappeared as humans with pigs and rats migrated throughout the tropical Pacific thousands of years ago.
In Hawaii, the Kona loulu or pritchardia, affinis or also known as pritchardia maideniana is a tree from Puna, Kona and Ka‘u. These palms were at one time found abundantly from Kalapana along the coast to Punaluu and the Kailua area of Kona, a distance of more than 150 miles. Today, only occasional isolated specimens can be found. Few seedlings appear around the parent plants. Without man’s help, they, too, will disappear. Another species, pritchardia schattaueri may also have been common at one time in upland areas of leeward Hawaii, but was reduced to just a few trees near Honomalino when identified as a new species late in the 2oth century.
Otto and Isa Degner published an article in June 1971 in Phytologia (Vol. 21) that speculates as to why the decline.
They wrote that on the island of Hawaii at Kaliilii, near Wahaula, within the Hawaii Volcanoes National Park, a few impressions of prostrate trunks can be seen on a prehistoric, though not very old, pahoehoe lava flow. Beyond the southwestern boundary of the National Park between the main road and the ocean, at Kawaa, lies an expanse of prehistoric, smooth pahoehoe. Here, the pahoehoe had gently flowed through a palm grove, the wet trunks burning slowly through the base so that the trees fell helter-skelter upon the cooling lava. The writers are convinced that the loulu reached the Hawaiian Islands some eons ago and may have more or less encircled many stretches of the islands with extensive groves, particularly before the Polynesians brought the pig and perhaps, as a stowaway, the seed-eating Polynesian rat. The fossil impressions at Kaliilii and above all at Kawaa are irrefutable proof of this fact.
By 1969, the Kona loulu, pritchardia affinis/maideniana was close to extinction along the Ka‘u coastline unless measures were taken to ensure its survival. Fortunately, C. Brewer and Company, Ltd., the major landholder in Ka‘u had just embarked on a resort development in the region and was developing a large nursery to supply materials for landscaping the project. The company was interested in locating and propagating plants adaptable to this dry, windy region. It was felt that the native plants of the region should have first consideration since they had proven their worth under Ka‘u’s climatic conditions.
In 1970, seeds of this palm were collected at the Beamer home adjacent to Punaluu Black Sand Beach. The seeds were planted in flats and grown to landscape size. Today, several groves are beautifying the Punaluu area of Ka‘u. Trees from this batch of seed also found their way to the King Kamehameha Hotel, Kona Outdoor Circle garden and many other sites around the island. Seeds distributed by the Hawaii Island Palm Society to California and even southern France and Morocco have been found to do well in protected locations.
Pritchardia affinis/maideniana is rarely found in the wild and only occasionally in the landscape. The most common types are the two introduced species from the south Pacific. These are pritchardia thurstonii and pritchardia pacifica. “Thurston’s loulu” is noted for flower clusters up to 6 feet long. Pritchardia pacifica has very large leaves that were used in the old days as sunshades and umbrellas. These species are adapted to dry coastal locations. The Kona loulu prefers sunny dryer locations but has been grown at elevations as high as 3,000 feet. The other rare one is named after George Schattauer, Kona kamaaina. A few trees are found above Kaohe, Honomalino and Hookena. This species and pritchardia beccariana from Kulani Prison Road near Volcano are being distributed on the Big Island. The latter is a spectacular rainforest palm with leaves almost six feet across. It prefers moist locations with wind protection. Many species have been tested at Kona Cloud Forest Sanctuary in Kaloko Mauka, North Kona and at Amy Greenwell Ethnobotanical Garden in South Kona.
It’s important to the survival of many of these beautiful species to use them in our gardens. Unfortunately, most nurseries do not carry the native loulus, and seed of some species are difficult to obtain.
To propagate loulus, plant fresh seeds in flats or shallow boxes filled with soil. Cover the seeds with from one-eighth to 1 inch of soil, depending on the size of the seed.
Keep the soil in the flats moist but not wet. Damping off fungi are likely to ravage the tiny seedlings if the soil is kept soggy.
Seed flats may be covered with clear plastic to keep in warmth and moisture. This will speed up germination. Be sure to keep seed and seedlings protected from rats.
Germination time of palm seed varies widely with the species and requires patience. They may not peek out of the ground for several months following planting.
Pot the plants into 1 gallon containers after they have sprouted. A suggested potting mixture is equal parts of soil or cinder and rotted compost. Fertilize monthly with a complete fertilizer.
When the seedlings are 1-2 feet high, transplant them to 5-gallon containers or plant them in the ground. Loulu palms are well suited for planting in groups, as specimens, or for lining driveways. Young palms require coddling until established, then they thrive with very little attention, other than sun, fertilizer and water.
Remember, if folks begin to show more interest in native trees such as the Loulu, our nurseries can then afford to carry them as part of their regular stock. County and state buildings and roadways are ideal for loulus since they do not have aggressive root systems. With the Queen Kaahumanu Highway widening project from Keahole Airport to Kailua, wouldn’t it be great to see the median strip landscaped with native loulu palms, kamani, naupaka and other natives. These palms and many other native plants should be used instead of grass that requires much more maintenance and water.
This information is supplied by the University of Hawaii College of Tropical Agriculture and Human Resources.