The herb and flower-heads of Spilanthes oleracea, Jacquin.
COMMON NAME: Para cress.
Botanical Source and Description.—The genus Spilanthes is a tropical family of (mostly) annual weeds, with opposite leaves, and terminal, stalked, flower-heads. It is closely allied to Bidens, differing, chiefly, in the achenia, which are plano-convex, with a membranous winged margin. The pappus consists of 2 short awns. The receptacle is conical and paleaceous. Spilanthes oleracea is a native of South America, and is often cultivated in tropical countries, where it is used as a salad. It is known under the name Para cress. It is a small, erect herb, of rapid growth, and has cordate stalked leaves. The flowers are small, yellow, and solitary, on terminal peduncles. The Chinese derive a blue coloring matter from Spilanthes tinctoria, Loureiro, similar to indigo. Spilanthes Acmella, Linné, an East Indian species, has properties akin to those of Spilanthes oleracea. Spilanthes oleracea has an acrid, aromatic taste, resembling, but more powerful than, peppermint. Analysis has shown it to contain volatile oil, an acrid resin, tannin, etc., and an alkaloid (Buchheim). When chewed spilanthes occasions a copious flow of saliva.
Action, Medical Uses, and Dosage.—Spilanthes is an acrid, aromatic sialagogue, and which, like the galanga root, has been recommended in flatulence, to improve the appetite and digestive functions, and to overcome nausea and vomiting. It may also be used in non-mercurial ptyalism, and in inflammations of the mouth and throat, using fractional doses of a strong tincture (recent herb, ℥viij to alcohol, 98 per cent Oj). The natives of the countries to which it is indigenous, are stated to have employed it advantageously in gouty and rheumatic affections, in uric acid gravel, in dropsical effusions, and even to remove intestinal worms. A tincture of it placed on cotton, and introduced into the cavity of a decayed tooth, will, it has been remarked, promptly relieve toothache. It is not employed in this country.