Casuarina

Better known as ironwood and introduced to Hawaii as early as 1872, this evergreen tree looks like a giant, sweeping brown pine tree. Its needle-like branchlets wrap around sheath-like leaves that themselves are utterly inconspicuous. Ironwood fixes free nitrogen from the air into its roots, and as a result it can grow in the poorest of soils. This served for it to become in Hawaii a favored reforestation tree. Reaching up to 100 feet, ironwood also delivers a timber that is hard and deep-red at its heart. Thousands of trees were planted in Hawaii in the early 1900s, including in Halawa. In the 1930s, ranchers planted a row of ironwoods along the Kohala Mountain Road, which connects Kohala to the town of Waimea, as a windbreak for the cattle.
Unfortunately, few other plants grow well under or near ironwoods, and the branchlets drop to form brownish carpets, which not everyone appreciates, but for Kohala Zipline a couple of these trees add immense value as platform trees with history.