Phlegmariurus mannii, synonym Huperzia mannii, is a species of lycopod, known by the common names Mann's clubmoss and wawaeʻiole. It is endemic to Hawaii, where there are only six populations remaining.[1] It is a federally listed endangered species of the United States.
This plant is an epiphyte which grows upon other plants, especially koa (Acacia koa), ʻolapa (Cheirodendron trigynum), and kawaʻu (Ilex anomala).[2] It has a hanging, branching, reddish stem no more than 10cm (00inches) long. Each branch has three longitudinal rows of toothlike leaves. When reproducing, the plant produces a branching fruiting spike which may be up to 20cm (10inches) long.[2]
Today the plant is known from just a few occurrences on the islands of Maui and Hawaii. It is historically known from Kauai, but it may be extirpated there.[1] Threats to its existence include damage to its habitat by feral pigs, cattle, and Introduced plant species, and the fact that there are few individuals remaining.[1] [2]