Cyperus pennatiformis

Cyperus pennatiformis (formerly Mariscus pennatiformis) is a rare species of sedge known by the common name coastal flatsedge. It is endemic to Hawaii, where it grows on the islands of Maui, Kauai, and Laysan. It is a federally listed endangered species of the United States. This sedge grows 40 centimeters to 1.2 meters tall with leathery leaves as long as the stem or longer. The flower cluster atop the stem is umbrella-shaped and up to 15 centimeters long by 25 wide. It contains up to 18 spikes which are each made up of several yellowish or grayish spikelets. The spikelet contains up to 25 flowers. Today, this plant grows on Maui, Kauai, and Laysan; it has recently been extirpated from Oahu and the island of Hawaii. The most recent surveys found about 30 individual plants on Maui and four populations on Kauai; these represent the subspecies pennatiformis. On Laysan the plants are of subspecies bryanii, known as Laysan sedge or Bryan's sedge. In 2008, a total of 488 individuals were co......read more on Wikipedia.