The living collections at Kahanu Garden focus on plants of the Pacific Islands, particularly those of ethnobotanic value to Hawaiians and other cultures of Polynesia, Micronesia, and Melanesia. Collections also include other plants native to the Hawaiian Islands, and to East Maui specifically.
Ethnobotanical collections are used for conservation, scientific research, and education, as well as some of them for consumption. ‘Ulu, Artocarpus altilis or breadfruit, is in the Moraceae, or Mulberry, family. This important conservation and research collection comprises 195 accessions and more than 120 varieties from 18 Pacific Island groups, Indonesia, the Philippines, and the Seychelles. It is the largest and most extensive collection of breadfruit varieties and species in the world, preserving some varieties that no longer exist in their native lands. Breadfruit is high in carbohydrates and low in fat; it is a good source of vitamins and minerals. It also provides medicine, construction materials, adhesives, insecticides, and animal feed. Scientists at NTBG’s Breadfruit Institute are studying the nutritional values of breadfruit and are conducting tissue culture experiments with cultivars from the collection at Kahanu with the goal of distributing plants to undernourished tropical nations.
The “Canoe Garden” collections include representatives of other traditionally important ethnobotanical plants that were brought to Hawai‘i by Polynesian settlers in their canoes as long as 1,800 years ago. These collections serve conservation, education, and research purposes. Planted around the heiau, they provide a context for understanding the Hawaiian people and the heiau itself. Kalo, Colocasia esculenta or taro, is a member of the Araceae, or Arum family. It is a staple food of Hawaiians and a cornerstone of their culture. Evidence of the importance of taro is the diversity of varieties (over 300 Hawaiian varietal names) cultivated by the Hawaiians over the centuries, each with its own name. It is immensely important to preserve not only these plants but also the cultural history associated with them.
Other important ethnobotanical plants include ‘uala, Ipomoea batatas or sweet potato, which is a member of the Convovulaceae, or Morning Glory family. Another staple food of Hawaiian culture, the sweet potato also has medicinal uses. It is the only Polynesian introduction that traces its origins to South America. Kō, Saccharum officinarum or sugar cane, is a member of the Poaceae, or Grass family. In addition to its cultural significance, sugar cane has played an important role in the economic history of Hawai‘i. ‘Awa, Piper methysticum or kava, is a member of the Piperaceae, or Pepper family. An important ethnobotanical plant, its roots are made into a relaxing drink that is used ceremonially and medicinally throughout the Pacific. The conservation collection of ‘awa at Kahanu Garden includes wild collections of Hawaiian cultivars as well as those from other Pacific Islands. Mai‘a, Musa sp. or banana, is in the Musaceae, or Banana family. Early Hawaiians ate bananas as a delicacy rather than a staple, with some varieties restricted to chiefs and priests and eaten on ceremonial occasions. This is an especially important conservation collection, as many Hawaiian banana cultivars are being lost due to diseases, pests, and development.
Niu, Cocos nucifera or coconut, is a member of the Arecaceae, or Palm family. It is often called the “Tree of Life” because of its many ethnobotanical uses. In addition to providing a source of food and water, coconut palm leaves are used for weaving and thatching, trunks for drums, shells for bowls and tools, and husks for straining liquids, starting fires, and making rope. The trees in the Mary Wishard Coconut Grove have been collected from many areas of the world including the Pacific. Because many of the trees have been infected by a fungus that is killing them, collaborative research is underway to identify disease-resistant individuals in the collection.
Kahanu Garden also contains collections of native Hawaiian plants of lowland Maui, which play important roles in conservation, research, and education. More than half of Kahanu Garden is covered by a forest of native hala, Pandanus tectorius, in the Pandanaceae, or Screw Pine family. This versatile plant has many uses, for housing, mats and baskets, and even sails for canoes. This, the largest remaining hala forest in the Hawaiian Islands with many native understory plants, serves conservation and educational purposes. It provides a glimpse into the past of the native landscapes of ancient Hawai‘i.
A collection of the East Maui loulū, Pritchardia arecina or fan palm, in the Arecaceae, or Palm family, is being planted as a conservation collection. This species of loulū is the only Pritchardia endemic to East Maui. Loulū leaves were used by the Hawaiians as thatch for traditional houses.