The noni tree is a native of Asia, Australia, and the islands of the Pacific. The noni was probably brought to Hawaii by the ancient Polynesians. The fruit and the leaves of this plant were used for medicinal purposes. The roots and the bark were used to make dyes. In ancient times, the mountain side of the trail was open land. The redtop ground cover is abundant today, but in the past, the native pili grass grew here. Pili grass is planted near the visitor center today.