Helianthemum. Rock-rose, Frost-weed. Helianthemum canadense.

Helianthemum. N. F. IV. Rock-rose. Frost-weed. Herbe de Heliantheme de Canada, Fr. Canadisches Sonnenröschen, Gr. Helianthemum canadense (L.) Michx.—"The dried herb of Helianthemum canadense (Linne) Michaux (Fam. Cistaceae)." N. F. Frostwort grows in all parts of the Eastern United States, preferring dry sandy soils. It is official in the National Formulary IV. The dried herb is employed in medicine and is described as follows: "Stems mostly less than 5 cm. in length, branched above, terete, frequently reddish, canescent, the slender branches mostly erect; leaves very short-petioled, from 1 to 3 cm. in length, and from 4 to 8 mm. in width, oblong to oblanceolate, with entire, revolute margins, green and somewhat rough on the upper surface, canescent underneath; flowers of two kinds, rarely present at the same time, the early ones mostly solitary, pedicelled, with bright yellow corolla, from 2 to 3 cm. in breadth, hairy calyx, about thirty stamens and a single three-carpelled pistil, producing an ovoid capsule, about 7 mm. in length; later flowers apetalous, clustered in the leaf-axils, nearly sessile, having but four stamens and producing a capsule about 4 mm. in length. Odor slightly aromatic; taste astringent and bitter." N. F. William Crutcher (A. J. P., 1888, 390) found in it volatile oil, wax, fatty oil, tannin, and apparently a glucoside crystallizing in white needles. Fred J. Kruell found in H. corymbosum, Michx., tannin in large proportion, resin, glucose, gum, extractive, chlorophyll, and inorganic salts. (A. J. P., 1874, 358.) Frostwort has an astringent, slightly aromatic, and bitterish taste, and appears to possess tonic and astringent properties; it was formerly employed in scrofulous diseases. (See U. S. D., 14th ed.) According to D. A. Tyler (Pamphlet, New Haven, 1846), H. corymbosum Michx. possesses similar properties, and may be indiscriminately employed with H. canadense in scrofula, diarrhea, and secondary syphilis, and locally as a gargle in scarlatina, and a wash in prurigo. Tyler, however, has known the strong decoction and the extract to produce vomiting. He considers two grains (0.13 Gm.) of the latter a full dose for an adult. The Fluidextractum Helianthemi is recognized by the N F. IV. (see Part III). The menstruum is diluted alcohol.

The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.