The Hawaiian Islands are one of the most geographically isolated landmasses in the world, creating a stunning biological hotspot. This isolation allowed many plant species to evolve into forms found nowhere else on Earth. Trees hold deep cultural meaning in Hawaiian history, traditionally serving as sources of life, providing materials for tools, shelter, and transportation. Understanding Hawaii’s trees requires appreciating both the ancient native species and the prominent introductions that characterize the modern landscape.
The Official State Tree
The official state tree of Hawaii is the Kukui, or Candlenut tree, designated in 1959. Known scientifically as Aleurites moluccana, it is not endemic but was introduced by early Polynesian voyagers, making it a “canoe plant.” The Kukui is easily identified by its pale, silvery-green leaves.
The tree’s common name comes from the historical use of its nuts, which are rich in oil. Ancient Hawaiians would string the dried kernels together and light them as torches. The oil was also used medicinally and as a varnish for canoes. Today, the durable, polished nuts are still widely used to create traditional lei.
Icons of the Native Forest
While the Kukui holds the state title, the true pillars of the native Hawaiian forest are the endemic species, such as the Koa and the ‘Ōhi‘a Lehua. The Koa (Acacia koa) is the largest native tree in Hawaii, capable of reaching heights over 100 feet.
Historically, Koa wood was highly valued, considered the wood of Hawaiian royalty, and used to craft large items like canoes (waʻa) and surfboards. Ecologically, Koa is a foundational species, enriching the soil by fixing nitrogen and providing a canopy that shelters understory plants. Its presence is also linked to the survival of endangered native forest birds.
The ‘Ōhi‘a Lehua (Metrosideros polymorpha) is the most common native tree, dominating approximately 80% of the native forest area. It acts as a pioneer plant, often colonizing barren lava flows first. The tree’s dense canopy is important for watershed health, capturing moisture from fog and regulating surface runoff to replenish aquifers.
The tree is sacred in Hawaiian culture and often associated with Pele, the goddess of volcanoes. Its vibrant lehua blossoms are traditionally used in lei. The ‘Ōhi‘a Lehua showcases remarkable resilience, adapting to nearly all habitats, from sea level to high elevations and from saturated bogs to dry slopes.
Prominent Introduced and Non-Native Species
Many trees associated with a Hawaiian vacation are visually prominent introductions, not native species. Coconut Palms (Cocos nucifera) are an iconic sight along the beaches but arrived with the earliest Polynesian settlers, making them an ancient introduction.
The Banyan tree (Ficus benghalensis), which originated in India, is known for its immense, sprawling canopy created by aerial roots that descend and form new trunks. These trees are often found in public parks and squares, such as the famous one in Lahaina, where their massive size creates a visual landmark.
The striking Rainbow Eucalyptus (Eucalyptus deglupta), native to the Philippines, draws attention due to its colorful bark. As the outer bark sheds, it reveals an inner layer of bright green that matures into vivid patches of blue, purple, orange, and maroon. Planted in the 1920s as part of reforestation efforts, this unique tree adds a splash of color to the Hawaiian landscape.