Viola helena, commonly known as Wahiawa stream violet, is a rare species of flowering plant in the violet family. It is endemic to Hawaii, where it is known only from the Wahiawa Mountains of Kauai.[1] It is threatened by exotic plant species and feral pigs. It is a federally listed endangered species of the United States.
Viola helena is a subshrub which can reach 8 meters in height. It has long, narrow leaves and pale purple or white flowers.[2]
This species is in decline and its numbers have dropped since the 1990s. There are two populations left, one of which was decimated by a landslide in 2005, leaving only a few seedlings and a seed pod. The other population, containing seven individuals, may be sterile and is too far from the first population to interbreed with it.[1]