**MASTERWORT**: A genus of the digynia order, belonging to the pentandria class of plants; and in the natural method ranking under the 45th order, Umbellata. The fruit is roundish, compressed in the middle, gibbous, and surrounded with a border; the petals are inflexo-emarginated. There is but one species, viz. the ostruthium, a native of the Austrian and Styrian Alps, and other mountainous places of Italy. Mr Lightfoot informs us, that he has found it in several places on the banks of the Clyde in Scotland; but whether indigenous or not, is uncertain. The root is as thick as a man's thumb, running obliquely in the ground; it is fleshy, aromatic, and has a strong acid taste, biting the tongue like pellitory of Spain: the leaves arise immediately from the root; they have long foot-stalks, dividing into three very short ones at the top, each sustaining a trilobate leaf, indented on the border. The footstalks are deeply channelled, and, when broken, emit a rank odour. The flower-stalks rise about two feet high, dividing into two or three branches, each being terminated by a pretty large umbel of white flowers whose petals are split; these are succeeded by oval compressed seeds, somewhat like those of dill, but larger.—The plant is cultivated in gardens for the sake of its roots, which are used in medicine. It may be propagated either by seeds, or by parting the roots in autumn. They thrive best in a shady situation.—The root has a flavour similar to that of angelica, and is esteemed a good sudorific. There are instances of its having cured the ague when the bark had failed. It should be dug up in winter, and a strong infusion made in wine.