Cyanea koolauensis (formerly Rollandia angustifolia) is a rare species of flowering plant in the bellflower family known by the common names Palolo Valley rollandia and narrowleaf rollandia. It is native to Oahu, where it is known only from the Koʻolau Mountains. It is a federally listed endangered species. Like other Cyanea it is known as haha in Hawaiian. This Hawaiian lobelioid is a shrub reaching 1 to 1.5 meters in height. It bears dark red flowers.