buckler-mustard, or Ballard Mitridate-mustard: A genus of the tetradynamia order, belonging to the filiculosa clas of plants; and in the natural method ranking under the 39th order, Siliquose: The filicula is flat-compressed, rounded, above and below two-lobed, and the leaves of the calyx are gibbous at the base.

Of this there are three species: the auriculata, with small pods joined to the style; the didyma, with a double orbicular pod diverging from the style; and the apula, with flowers growing in spikes, and a shorter style. They are natives of France, Italy, and Germany.