The words "exotic" and "Hawaiian" often go hand in hand. If you're looking for seeds of native Hawaiian plants, you can find some along roadsides or in vacant lots in urban areas, but you must first know what you're looking for. If you want to collect seeds in undeveloped areas such as forests and jungles, you must have a permit from the Hawaii State Department of Land and Natural Resources, Division of Forestry and Wildlife. However, special nurseries and Web sites exist that provide landscape architects and sometimes members of the public with seeds of some of Hawaii's rare and exotic plants.
Visit a Hawaiian plant nursery. Sometimes botanical gardens sell or share seeds, so check with Lyon Arboretum and Waimea Valley Arboretum on Oahu, Amy Greenwell Ethnobotanical Garden in Kona on the Big Island, Kauai Nursery and Landscaping Inc. on Kauai and Maui Nui Botanical Gardens on Maui.
Search for Web sites that sell seeds of Hawaiian plants. SeedsHawaii.com carries numerous species, including plants that are native to Hawaii and others such as schefflera, Malabar chestnut, coffee, macadamia nut, many palms and other exotic plants.
Ask friends and neighbors if they have any exotic Hawaiian plants growing in their yards. If so, identify the species and research what the seedpods look like and at what time of year these plants are likely to produce mature seeds. Collect them at that time, allow them to dry, then plant them according to their specific needs.
Obtain a gathering permit from the State Department of Land and Natural Resources, Division of Forestry and Wildlife if you know what type of plant you want and about where it grows. The State website cautions that "special restrictions apply," and that you must telephone their office on your island to obtain a permit.