Genus Amaranthus
Amaranthus, collectively known as amaranth, is a cosmopolitan genus of herbs.Species in the genus Amaranthus of plants
Brown's amaranth - It is one of 26 vascular plants on Nihoa, 17 of which are indigenous, six alien, and three endemic only to Nihoa, including A. brownii, the Nihoa Fan Palm or loulu, and the Nihoa Carnation. A. brownii is considered the rarest plant on Nihoa and has not been directly observed on the island since 1983. Past expeditions collected plant samples and seeds, but no specimens have managed to survive ex-situ conservation efforts outside of its native habitat. There are no known plants or seeds from A. brownii in any botanical gardens.