Poa mannii is a rare species of grass known by the common names Mann's bluegrass and Olokele Gulch bluegrass. It is endemic to Hawaii, where it is limited to the island of Kauai. It is threatened by the loss and modification of its habitat. It is a federally listed endangered species of the United States.There are three species of Poa native to Hawaii, and they are all endemic to Kauai. There are at least 13 populations of this species, totalling about 100 individuals.