Spec. Plant Willd. ii. 1112. Cl. 12. Ord. 5. Icosandria Polygynia. Nat. ord. Rosaceae. G. 1001. Calyx three-cleft. Petals four. Seeds roundish, naked, affixed to a small juiceless receptacle. Species 1. P. erecta.1 Common Tormentil, or Septfoil (officinalis).

Smith, Flora Brit. 552. Eng. Bot. t. 863. Med. Bot. 2d edit.

503. t. 181. Officinal. Tormentillae radix, Lond. Edin. Tormentilla officinalis, Dub. Tormentil root.

Syn. Tormentil (F.), Tormentilwurzel (G.), Meerwortel (Dutch) Blodrot (Swed.), Kurzeziele (Pol.), Tormentilla (I., S., Port.), Sabiasnoi koren (Russ.).

This is a very common, indigenous, perennial plant, growing in dry pastures and on heaths; flowering in June and July. The root is woody : the stems are erect, branched, diffuse or procumbent, round and leafy. The leaves are nearly sessile, ternate, lanceolate, serrated, and hairy, accompanied by deeply incised stipules. The flowers are on long, capillary, opposite, solitary, one-flowered peduncles; the calyx consists of ovate, hairy, alternately larger and smaller segments, the latter of which are exterior; the petals have short claws, are obcor-date, and of a golden-yellow colour: the seeds are few and wrinkled.

Qualities.-The root has a very slightly aromatic odour, and an austere styptic taste. It is knotty : externally blackish, and internally reddish. To boiling water it yields its active matter, which appears to be chiefly tannin, as the infusion is copiously precipitated by solution of isinglass, and strikes a deep black with sulphate of iron. Except galls and catechu, it contains more tannin than any other vegetable.

Medical properties and uses. - Potentil root is a powerful astringent. It has been employed with success in intermit-tents, but more efficaciously in diarrhoeas; particularly those attendant on phthisis, as it produces its astringent effects without increasing the general excitement. As a local remedy it may be advantageously used in the form of gargle and lotion in ulcerations of the tongue and mouth, against spongy gums, and as an application to fetid, ill-conditioned sores; but it is seldom used. It may be given in substance, or in the form of decoction. The dose of the powdered root is from 3 ss. to 3 j.