The name Ambrosia was applied by Dioscorides and Pliny to certain herbs, and has been retained in modern botany for a genus of plants from which it has been extended to the group of dicotyledons called Ambrosiaceae, including Ambrosia, Xanthium and Iva, all annual herbaceous plants represented in America. Ambrosia artemisiofolia is the common American ragweed that brings so much misery to allergy sufferers with its anemophilous pollen. Ambrosia maritima and some other species occur also in the Mediterranean region.