DISTAFF THISTLE; a genus of the polygamia equalis order, belonging to the syngenesia class of plants.

Species. 1. The cancellata, or small cnicus, is an annual plant rising about eight or nine inches high, with a slender stem, garnished with hoary leaves, having spines on their edges. At the top of these branches are sent out two or three slender stalks, each terminated by a head of flowers like those of the thistle. The empalement is curiously netted over, and is narrow at the top, but swelling below; and contains many florets of a purplish colour. These are each succeeded by a single downy seed, which in cold years do not ripen in this country. 2. The humilis, or purple prickly cnicus, rises about a foot high, with indented leaves, having small spines on their edges. The upper part of the stalk is divided into two or three slender branches, each supporting a head of purple flowers, having rays inclosed in a fealy empalement. The flowers appear in June; but unless the season is warm, the seeds will not ripen in this country. 3. The gummifiera, or prickly gum-bearing cnicus, known among physicians by the name of earline thistle. This sends out many narrow leaves, which are deeply serrated, and armed with spines on their edges. These lie close on the ground; and between them the flower is situated, without a stalk, and having many florets inclosed in a prickly empalement. Those on the border are white; but such as compose the disk are of a yellowish colour. It flowers in July, but never perfects seeds in Britain.

Culture. All these plants are natives of the warm parts of Europe, as Spain, Sicily, and the Archipelago islands, from whence their seeds must be procured. They must be sown upon an open bed of light earth, where the plants are to remain; and when the plants come up, they should be thinned, so as to leave them three or four inches asunder. The roots of the second will last two or three years, and the third is a perennial plant.

Medicinal Uses. The root of the third sort was formerly used as a warm diaphoretic and alexipharmic; but it never came much into use in Britain, and the present practice has entirely rejected it. The root is about an inch thick, externally of a pale rusty brown colour, corroded as it were in the surface; and perforated with numerous small holes, so as to appear worm-eaten when cut. It has a strong smell, and a subacid, bitterish, and weakly aromatic taste. Frederic Hoffman the Elder, relates, that he has observed a decoction of it in broth to occasion vomiting.