AMARANTHUS, in botany, a genus of the monœcia pentandra class. The flowers have no petals; the calix is multifid; and the seeds are contained in membranaceous vessels, and very numerous. There are 22 species of amaranthus, none of them natives of Britain, except the blitum, or lesser blite; all the others are found in the Indies. The amaranthus is said to be astringent.