Amaranthus brownii

Amaranthus brownii was an annual herb in the family Amaranthaceae. The plant was found only on the small island of Nīhoa in the Northwestern Hawaiian Islands, growing on rocky outcrops at altitudes of 120–215 m (394–705 ft). It was one of nine species of Amaranthus in the Hawaiian Islands, as well as the only endemic Hawaiian species of the genus. It is now considered extinct. A. brownii was first discovered during the Tanager Expedition in 1923 by botanist Edward Leonard Caum. It differed from other Hawaiian species of Amaranthus with its spineless leaf axils, linear leaves, and indehiscent fruits. It was one of 26 vascular plants on Nīhoa, 17 of which are indigenous, six alien, and three endemic only to Nīhoa; these latter three included A. brownii, the Nīhoa fan palm or loulu, and the Nīhoa carnation. A. brownii was considered the rarest plant on Nīhoa and was not directly observed on the island after 1983. Past expeditions collected plant samples and seeds, but no specimens managed......read more on Wikipedia.