A revision of the genusCharpentiera (Amaranthaceae) is presented, based upon field and herbarium studies, with evidence from anatomical and cytological studies. Eight taxa are recognized. Populations of the genus are found on six of the main Hawaiian Islands and on the Austral Islands of Tubuai and Raivavae, representing a disjunction of about 2800 miles. Keys to the taxa, descriptions, distribution maps, and illustrations are provided. New taxa areC. australis,C. densiflora,C. tomentosa var.tomentosa,C. tomentosa var.maakuaensis,and C. ovata var.niuensis.