Pinguicula vulgaris and Pinguicula alpina.
Pinguicula Vulgaris and Pinguicula Alpina L. (Fam. Lentibuliariaceae.)—These perennials of the northern United States and Canada are used as a folk medicine in the treatment of wounds and as a purgative. It has been asserted that P. vulgaris contains a proteolytic ferment; this has been used in combination with the extract of thyme in the treatment of whooping-cough under the name of "diatussin." The dose of diatussin for a child of five years is one to three drops twice a day.