n. plTetradynamia(Bot) A Linnæan class of plants having six stamens, four of which are longer than the others.
Century Dictionary and Cyclopedia
tetradynamiaThe fifteenth class in the Linnean system, comprehending those plants which bear hermaphrodite flowers with six stamens, four of them longer than the other two. It was divided into 2 orders—Siliculosa, of which the common garden-cress and shepherd's-purse are examples, and Siliquosa, of which the mustard and cabbage are examples. All the plants of this class are now included in the natural order Cruciferæ.
Webster's Revised Unabridged Dictionary
NL., fr. Gr. te`tra-see Tetra-) + power
Sydenham recommends vegetables of the class Tetradynamia in rheumatic pains left after the cure of intermittents.