CLYPEOLA, TREACLE-MUSTARD; a genus of the filiculosa order, belonging to the tetradymania class of plants. There are two species, both natives of France, Italy, and the warm parts of Europe, but hardy enough to bear the winters in this country. One of them is an annual, and the other a perennial plant; both are low and herbaceous, bearing spikes of white flowers. They are propagated by seeds, which should be sown in autumn where they are to remain.