Some Woods of Hawaii Koa - (Acacia koa) Koa is the largest endemic tree in Hawai‘i–the species exists naturally nowhere else in the world. It is the fastest growing of Hawaii’s valuable hardwoods. It can grow as much as an inch in diameter per year, reaching 100 feet in height, attaining a trunk diameter of 5 feet or more. It was historically the material of choice for carved ocean-going canoes. Koa wood is the most prized cabinet and furniture wood in Hawai‘i. Colors range from light brown to deep red/brown hues. Highly figured koa is sought after for use in fine furniture, musical instruments, crafts, gunstocks, and knife handles. Koa has weight and strength properties similar to black walnut. It is a moderately heavy wood (specific gravity .55). It is stable, works well, and takes an exceptionally rich, deeply reflective glow when finished with oils and modern varnish or laquer. Ohi‘a lehua (Metrosideros polymorpha) The ‘Ohi‘a is unique to Hawai‘i. It is one of the trees initially used by native Hawaiians for critical construction applications such as tools, and wear-strips along the gunwales of canoes. Its modern applications are typically in flooring, furniture and cabinetry. It is the most common endemic tree in the state, can be a major component of mixed forest stands, and is one of the very first trees able to take root on new lava fields. The tree is present in shapes ranging from shrubs to 100 feet in height. The wood ranges in color from pale brown to a dark reddish brown. It is fine grained, very hard, strong, and dense (specific gravity .70) In furniture and cabinetry applications, ‘Ohi‘a is nearly indestructible. However, great care and experience must be brought to bear in the seasoning of this notoriously unstable wood. Robusta eucalyptus (Eucalyptus robusta) Robusta is the most commonly planted of over 100 eucalyptus species introduced to Hawai‘i. It is a moderately large tree, 50 to 160 feet in height, and up to 4 feet in diameter. The wood is light red in younger specimens, and runs to a deep, dark mahogany red in older trees. The mature wood is very hard, and typically very heavy (specific gravity .8). It compares to white oak in most strength properties. As with many of the eucalypts, successful processing of E. robusta is achieved by eliminating the brittle wood near the pith. In fine furniture applications Robusta is extremely durable, typically finishes with a deeply reflected glow, and ages over time to a rich mahogany color. The fanciest grade of quartersawn E. robusta lumber has a dramatic “block mottle” figure resembling a checkerboard of parallelograms. Saligna eucalyptus, Flooded-gum (Eucalyptus saligna) This tree grows to 200 feet in height with a trunk diameter up to 4 feet. Since 1880, it has been widely used for forestation in Hawai‘i. The wood is moderately heavy (specific gravity .61, with mature wood over 50 years old approaching .75), and runs from pale brown through pink in color, and tends to darken when finished. The wood is fine grained, and resembles cherry in many applications. The grain tends to be straight to strongly interlocked, and may show distinct ribbon-striped figures on quarter-sawn faces. Toon (Toona ciliata) Toon was introduced in 1918 for plantation use. It grows to 50 feet tall and reaches over two feet in diameter. The wood is very lightweight (specific gravity .35), and is reddish brown. The tree is also called “Australian red cedar”, because of the strong aromatic cedar scent of the wood. It carves and turns particularly well. There are several stands in Hawai‘i forest plantations. Tropical ash (Fraxinus uhdei) Tropical ash was originally introduced in 1880 as a shade tree, but has been planted in Hawai‘i as a forest and watershed cover tree since the 1920s. It grows to about 80 feet in height and three feet in diameter. The wood is white and similar to white ash, but is moderately hard and light weight (specific gravity .47). It has applications in furniture for its especially light coloring and fine grain. More of the wood is expected to be available from state plantings in coming years.