Drosera. Sundew. N. F. IV. Herba Rorellae. Rosollis. Rosee du Soleil, Fr. Sonnenthau, G.—It is described by the N. F. as "the air-dried flowering plant of Drosera rotundifolia Linne (Fam. Droseraceae), frequently mixed with the closely allied species Drosera intermedia Hayne and Drosera longifolia Linne, or at times wholly replaced by these. A delicate plant of a reddish color throughout, with few fibrous, blackish rootlets; leaves all in a basal rosette, blade orbicular, about 15 mm. in diameter, abruptly contracted into a slender, pubescent petiole, upper surface covered with prominent glandular hairs; scape filiform, smooth, from 10 to 20 cm. in length, bearing a few, five-parted, small, white fugacious, flowers in a curved, one-sided raceme. Drosera intermedia is identified by its spatulate leaves with blades two or three times as long as they are wide and glabrous petioles. Drosera longifolia is identified by its elongated spatulate obovate leaves with blades six to eight times as long as they are wide, and its slender smooth petioles and scape, declinate at base. Odorless; taste faintly bitter and acidulous. Drosera yields not more than 30 per cent. of ash." N. F. Drosera has been employed in phthisis, but is probably of no value. (See Proc. A. Ph. A., xxvii, 225.) Under the name of droserin an extract of various plants of this species has been recommended in whooping cough. It is marketed in the form of tablets of which there are two strengths; number one being intended for children, number two for adults. The dose of the crude drug is one drachm (4 Gm.).