Cyanea grimesiana, commonly known as splitleaf cyanea or haha, is a rare and endangered shrub endemic to the moist, shaded forests of the Hawaiian Islands, specifically on Oahu and Molokai. It can exceed three meters in height and is characterized by its prickly stems and foliage. The plant produces tubular flowers up to 3 inches long, which may be purple, green, or yellow with reddish stripes, and are notable for their size and unique coloration. The flowering season typically occurs in the summer months. Following pollination, it bears an orange berry that is significant for local wildlife. In its native habitat, splitleaf cyanea thrives in understory conditions of tropical montane forests.

Splitleaf cyanea is valued for its unique appearance and its role in native plant conservation. Due to its rarity, it is not commonly used in general cultivation but is of high interest in botanical gardens and among conservationists. It requires consistently moist soil, partial to full shade, and protection from wind. Given its conservation status, it is not recommended for widespread cultivation to avoid genetic dilution of wild populations. Cultivation should focus on preserving genetic diversity and supporting recovery efforts.CC BY-SA 4.0