Hawaii’s diverse landscape nurtures an array of impressive trees, ranging from towering native species deeply rooted in the islands’ ecosystems to introduced giants that have become iconic features. These magnificent trees contribute significantly to the islands’ unique botanical character, offering both ecological benefits and breathtaking visual appeal. Their substantial size and distinct forms create a powerful presence within the varied Hawaiian terrain. These arboreal wonders reveal the rich natural heritage and plant life across the archipelago.
Hawaii’s Towering Native Trees
Among Hawaii’s indigenous flora, the Koa (Acacia koa) stands as the largest native tree. These trees typically reach heights of 15 to 25 meters (49 to 82 feet), with some specimens growing up to 30 meters (98 feet) in optimal volcanic ash soil conditions. Koa trees can develop stem diameters up to 1.5 meters (5 feet), with older trees exhibiting trunks 3 to 7.6 meters (10 to 25 feet) in diameter, forming broad, spreading crowns. The mature tree is distinguished by its sickle-shaped phyllodes, which function as leaves. Its prized reddish-brown wood was historically used by Hawaiians for crafting canoes and is now valued for fine furniture.
Another widespread native giant is the ʻŌhiʻa (Metrosideros polymorpha), which constitutes about 80% of Hawaii’s native forests. This resilient tree grows 20 to 25 meters (66 to 82 feet) tall. The ʻŌhiʻa is well-adapted to varied environments, thriving from sea level to 2,400 meters (8,000 feet) and often being the first woody plant to colonize new lava flows. Its vibrant flowers, ranging from fiery red to yellow, are a mass of stamens and provide nectar for native birds. The tree itself plays an important role in watershed protection by retaining water and preventing erosion.
Impressive Introduced Giants
Hawaii’s landscape is also graced by several introduced tree species that have grown to immense proportions, becoming notable landmarks. The Banyan (Ficus benghalensis), originally from India, is characterized by its remarkable aerial roots that descend from branches and root into the ground, forming new trunks. These trees can cover vast areas, providing significant shade.
The Rainbow Eucalyptus (Eucalyptus deglupta), native to the southern Philippines, is known for its uniquely colorful bark. As the outer bark peels away, it reveals an inner layer that changes from bright green to shades of blue, purple, pink, orange, and maroon. These fast-growing trees can reach heights of 30 to 60 meters (100 to 200 feet) and trunk diameters up to 1.8 meters (6 feet).
The Monkeypod (Samanea saman), introduced from Central and South America in the 1850s, is recognized by its wide, umbrella-shaped canopy. This canopy can spread 24 to 30 meters (80 to 100 feet) across, with some specimens reaching 61 meters (200 feet). Monkeypod trees typically grow up to 24 meters (80 feet) tall. Their bipinnate leaves fold inward at night or during cloudy weather, giving rise to its alternative name, “rain tree.”
Notable Locations for Viewing These Trees
Visitors can experience Hawaii’s large trees firsthand at several locations across the islands. On Maui, the historic Lahaina Banyan Tree, planted in 1873, is a prominent example, covering nearly an entire city block. Although significantly impacted by the 2023 wildfires, recovery efforts are underway for this landmark.
The Rainbow Eucalyptus trees can be found along the scenic Road to Hana on Maui, at the Keahua Arboretum on Kauai, and near Kaloko Drive on the Big Island. On Oahu, the Wahiawa Botanical Garden and Dole Plantation are also home to groves of these colorful trees.
For those interested in native Hawaiian trees, Oahu’s Lyon Arboretum in Manoa Valley showcases a collection, including mature Koa trees and various native species. The Big Island offers Lava Tree State Park, where lava flows in 1790 encased and preserved the molds of ‘Ōhi’a trees, creating natural sculptures. Additionally, Banyan Tree Drive in Hilo, on the Big Island, features a collection of banyan trees planted by historical figures.