The Flowering Plants of Hawaii
Part 13 Clusiaceae - Combretaceae - Convolvulaceae
Clusiaceae, perhaps recognized by some readers as the Guttiferae, are a primarily New World family from warm and tropical habitats with 1,150 species arrayed in 30 genera. A species that would likely be known to many readers is Hypericum perforatum, St. John’s wort to those interested in its biological properties, or Klamath weed to those more concerned about its weediness. Contact with this plant can cause photo-sensitized reactions in some individuals and is toxic to range animals for that reason. St. John’s wort and four other species of Hypericum have become naturalized on the islands. Another member of the family that has gained a measure of fame is Garcinia mangostema, commonly known as mangosteen, whose fruit is highly prized by many. The tough husk of the mangosteen contains high concentrations of antioxidants (primarily xanthones) preparations of which are widely available through health food and natural medicine outlets. Mangosteens are available in food stores in the islands but there is no report of the species having become naturalized.
A member of the family that has become naturalized is Clusia rosea, the autograph tree. This odd common name derives from the attractiveness of this plant’s leaves (see image), which are thick and waxy, to serve as a medium for the carving of initials, or other messages. The Manual reports its presence on Kaua`i, O`ahu and Hawai`i. There are examples (with messages) in the Limahuli Botanic Garden, and I have seen it near Dixie Maru Beach on the west coast of Moloka`i, where the photograph was taken.
The last example from this family is a Polynesian introduction, the kamani tree, Alexandrian laurel in English. Kamani is Calophyllum inophyllum (see image). This tree grows naturally on the shores of the Indian and western Pacific Oceans and was well known to the peoples of Polynesia. Readers familiar with the large yellow flower of St. John’s wort will recognize the characteristic family floral architecture in kamani. Krauss (1993) describes the many roles played by kamani in Hawaiian life. Kamani oil was used to polish coconut bowls as well as a source of light along with, or in place of, kukui nut oil. The wood was prized for the manufacture of bowls because it didn’t impart an unpleasant taste to foods as did vessels made from koa. The flowers, which possess an orange blossom-like aroma, were used as a perfume and the flowers themselves were important for making leis. The Manual states that kamani had important medical uses but I have not been able to find specific references.
The Hawaiian Islands are home to two species of Terminalia, both of which have become naturalized. Terminalia myriocarpa was one of the hardwood species planted on the islands some years ago as one of many projects undertaken by state foresters. (Many of the 200 or so species in the genus yield commercially useful timber.) The species of interest to us here is T. catappa, commonly known as Indian almond, Barbados almond, or wild almond in English, false kamani, kamani haole, or kamani `ula in Hawaiian (haole is foreign; `ula is red). The kamani referred to here is Calophyllum inophyllum (Clusiaceae), which we met above. Terminalia catappa has been extensively planted along the coast where it flourishes. It is salt-tolerant and its seeds may be disseminated by flotation. The trees provide excellent shade as anyone who has visited Ke`e Beach on Kaua`i knows (see image). Older leaves turn a brilliant red color to provide a striking contrast with the blue of the sky. The seeds are edible, as the common name suggests. The image shows a grove of seedlings along the trail in Pololü Valley on the far northeastern coast of the Big Island
The morning glory family, Convolvulaceae, are represented on the islands by species that have escaped from cultivation, others that occur throughout the Pacific, others that were or were thought to have been brought by Polynesian colonizers, and by one that is an island endemic. The island endemic species belongs to the tropical genus Bonamia which consists of 45 species. The sole member in the Hawaiian Islands is the rare B. menziesia (see image) known from dry habitats on all of the main islands except Ni`ihau and Kaho`olawe.
Likely the most familiar, and easiest to see in its native habitat, is Ipomoea pes-caprae (see image), the beach morning glory, or pöhuehue in Hawaiian. This species occurs throughout the Pacific and can be found on nearly any sand beach that hasn’t been degraded by development, Barking Sands on the western coast of Kaua`i west coast, some of the beaches on the southern and northern coasts of Moloka`i. Early Hawaiians stripped the long vines of their leaves and used them to make strong ropes for handling canoes, while shorter bits found use in house construction.
A second indigenous morning glory, I. indica, can be found in dry, often disturbed, sites such as occur on the western slopes of Mt. Kahala where the photograph was taken. It occurs in similar habitats on all of the islands. Hawaiian names for I. indica include koali `awa, koali `awahia, koali lä`au, and on Ni`ihau, koali pehu. Koali is a generic term for some kinds of morning glories I have looked for but never found, at least in flower—wrong time of day, wrong season, bad luck—the Hawaiian endemic species I. tuboides (see image below). This species grows on lava and rocky slopes, areas that I regularly visit. It’s called the Hawaiian moon flower. Ipomoea batatus, the sweet potato, or `uala and `uwala in Hawaiian was an important Polynesian food plant brought to the islands by the earliest colonizers (see image), here seen growing in the Polynesian plant section of the NTBG. Ipomoea tubiflora (see image) is a native of the West Indies now naturalized in the tropics. Seeds of this species are often found as contaminants of rice seeds.
Jacquemontia ovalifolia is a primarily dry land species widespread in the Pacific. The plants in the Hawaiian Islands are sufficiently different to be recognized as the endemic J. ovalifolia subsp. sandwicensis (see image). Hawaiian names for this highly variable species include pü`üohi`iaka, käkuaohi`iaka, and kamo`o.
November , 2011