or Horn-flower, a genus of the order of algae, belonging to the cryptogamia class of plants. The calyx of the male is fiddle, cylindrical, and entire; the antherae are very long, subulate, and two-valved; the calyx of the female is divided into six pieces; the seeds are three. There are only three species of the anthoceros, viz. the punctatus or spotted anthoceros, a native of Britain; the levis, a native of Europe and America; and the multifidus, a native of Germany. It is found in moist shady places, and on heaths.