(from δώδεκα, twelve, and ανήρ, a man); the name of the eleventh class in Linnaeus's sexual system, consisting of plants with hermaphrodite flowers, that, according to the title, have twelve stamina or male organs. This class, however, is not limited with respect to the number of stamina. Many genera have sixteen, eighteen, and even nineteen, stamina; the essential character seems to be, that in the class in question, the stamina, however numerous, are inserted into the receptacle; whereas in the next class, icosandria, which is as little determined in point of number as the present, they are attached to the inside of the calyx or flower-cup.

The orders of this class, which are fix, are founded upon the number of the styles, or female organs. Abaracca, mangotan, storax, purple loofefrife, wild Syrian rue, and purflain, have only one style; agrimony and heliocarpus have two; burning thorny plant, and bastard rocket, three; glinus, five; illicium, eight; and house leek, twelve.