Helianthemum Canadense. (Cistus Canadensis.)
Nat. Ord.— Cistaceae. Sex. Syst.— Polyandria Monogynia.
Description. — This plant is also known by the names of Rock-rose, Frost-plant, etc. It is herbaceous, and perennial, with a slender, rigid, pubescent, ascending stem, from six to eighteen inches high, and having erect, pubescent branches. The leaves are alternate, from eight to twelve lines long, and about one-fourth as wide, oblong, somewhat lanceolate, erect, entire, subsessile, tomentose beneath, and without stipules. The flowers are large and bright yellow; those which first appear are terminal, few or solitary, on short peduncles, with erosely-emarginate petals, about twice as long as the calyx ; at a later period the flowers are very small, axillary, solitary or somewhat clustered, nearly sessile, sometimes destitute of petals, and usually wanting the two outer sepals of the calyx. Stamens declinate. The fruit is a smooth, shining capsule, with brown, scabrous, punctate seeds ; the capsules of the apetalous or later flowers, not larger than a pin's head.
History. — This plant grows in all parts of the United States, in dry, sandy soils, and flowering from May to July. The whole plant is officinal. The leaves and stems of the plant are covered with a white down, and Eaton states that, in the months of November and December, he has seen these plants sending out, near the root, broad, thin, curved ice crystals, about an inch in breadth, which melted in the day, and were renewed in the morning. The plant has a bitterish, astringent, slightly aromatic taste, and yields its properties to hot water.
Properties and Uses. — This plant has long been used by Eclectics as a valuable remedy for scrofula, in which disease it has effected some astonishing cures. It is used in the form of decoction, syrup, or fluid extract ; if taken in too large doses it will sometimes vomit. It is tonic and astringent, as well as antiscrofulous. In secondary syphilis, either alone, or in combination with Corydallis Formosa, and Stillingia, it forms a most valuable remedy. The decoction may be employed with advantage in diarrhea, as a gargle in scarlatina and aphthous ulcerations, as a wash in scrofulous ophthalmia, prurigo and other cutaneous diseases. Externally, a poultice of the leaves is applied to scrofulous tumors and ulcers. The fluid extract is the best form for internal use ; dose, one or two fluidrachms, three or four times a day. A physician in the west, writes to me, that he procures an oil from this plant, which he finds valuable in cancerous affections ; how he prepares it is not stated. The H. Corymbosum or Frost-weed, with an erect, branching, canescent stem; lance-oblong, alternate leaves, canescently tomentose beneath ; the flowers in crowded, fastigiate cymes ; the primary ones on elongated, filiform pedicels, and with petals twice longer than the calyx ; sepals villous-canescent, outer ones linear, obtuse; inner ones ovate, acute; is found growing in pine-barrens and sterile sands, in the Southern and Middle States. It possesses properties analogous to the preceding, and may be indiscriminately employed with it.
Off. Prep. — Decoctum Helianthemi.