Puu Kukui is a mountain peak in Hawaii. It is the highest peak of Mauna Kahalawai, or the West Maui Mountains. The 1,764-m (5,788 feet) summit rises above the Puu Kukui Watershed Management Area, an 8,600-acre (35 km²) private nature preserve maintained by the Maui Land & Pineapple Company. The peak was formed by a volcano whose caldera eroded into what is now Īao Valley.
Puu Kukui is one of the wettest spots on Earth, receiving more than 355 inches (900 cm) of rain a year.
Puu Kukui is home to numerous endemic plants, insects, and birds, including the greensword (Argyroxiphium grayanum), dwarf 'ohia (Metrosideros polymorpha ) and many species of lobelia. Because of the mountain peak's extreme climate and peat soil, many species, such as the 'ohia, are represented as dwarfs. Access to the area is restricted to researchers and conservationists.