Thistle, or Carduus, L. a genus of plants, comprising 38 spe-cies ; 10 of which are indigenous : the following are the principal :

1. The marianus. See Milk Thistle.

2. The lancrolatus, or Spear-Thistle, grows on rubbish, and road-sides, where it flowers in the months of July and August. - According to Dr. Withering, this species vegetates on ground newly turned up, where no other v. will thrive: under the shelter it affords, new plants will speedily appear, and the whole become fertile. Its flowers, like those of the artichoke, possess the property of curdling milk. It is not relished by horses, cows, or goats; and is totally refused by sheep and swine.

3. The acaulis, or DwarF-thistle, thrives in mountainous and rocky, dry pastures; flowering in the month of July. - This species is perennial, and should be carefully extirpated; as it is exceedingly destructive to the herbage growing beneath its shade. It is wholly rejected by cows.

4. The Benedictus, or Blessed Thistle, is an annual exotic, cultivated in gardens: it flowers in the months of June and July, and produces ripe seeds in autumn. - Its leaves possess a penetrating bitter taste, and have an ungrateful flavour which, by keeping them for some time, is mostly dissi-pated. A decoction of this nauseous plant is sometimes used to excite vomiting; and likewise a strong infusion, to promote the operation of other emetics. Good effects have occasionally been derived from the Blessed Thistle, in loss of appetite ; or where the stomach was impaired by irregularities. A strong infusion, either in cold or warm water, drunk freely, occasions a copious perspiration, and promotes the secretions.

All the species of this neglected vegetable, may be usefully employed for various purposes : thus, the seed-crowns of the thistle afford both a valuable material for manufacturing Paper, and a kind of strong cloth ; the ashes obtained by burning the whole plant, are of great service in glass-houses ; and the young, tender, mealy stalks may be dressed, and eaten, as substitutes for asparagus.

Thistle, the Cotton, Common Argentine, or Woolly Onopordum, Onopordon Acan-thium, L. a native biennial, growing to the height of 6 feet, on rubbish, and road-sides, where it flowers in July. This vegetable is refused by cows, horses, and sheep : - its expressed juice, was among the ancients reputed to be a specific in cancerous cases : - the receptacles or bases of the flower-cups, together with the stems, may be boiled and eaten like artichokes. - The woolly substance enveloping the seed, is equally useful in the manufacture of cloth and Papek, (see vol. iii. p. 335). - The seeds of this remarkable plant also promise great advantages to the industrious husbandman : we learn from Durande, a French writer, in the Bibliotheque Physico-economique, vol. ii. p. 122, that he collected a number of the seed-crowns, weighing 22 lbs.; from which he obtained 12 lbs. weight of seed ; and, on expression, 3 lbs. of excellent lamp-oil, greatly superior to that of linseed, and equal to olive-oil.

Thistle, the Sow. See Sow-Thistle.