THISTLE. This term, as generally employed, is of vague application, being given to almost any herbaceous plant that is of a spiny character. More strictly, it is ap plied to the species of Carduus. These are Composite herbs with very spiny leaves, and similar bracts surrounding a head of purplish-white, tubular, 5-parted flowers seated on a pitted and hairy receptacle. The anthers have appendages both at the apex and at the base. The style has a ring of hairs at the point of bifurcation of the two stigmata. The fruit is surmounted by a tuft of silky white hairs. The species are numerous, and some are of great beauty, though not unnaturally looked on with disfavour by the farmer. The Cotton Thistle, remarkable for its covering of white down, is Cnopordon Acanthium ; the Blessed Thistle is Carduus benedictus ; the Holy Thistle, the leaves of which are spotted with white, is C. Marianus. The common C. lanceolatus seems to be the most suitable prototype for the Scotch Thistle, though that honour is also conferred on Cnopordon Acanthium, the cotton thistle, a doubtful native, and on other species. The great objection to thistles from an agricultural point of view resides in the freedom with which they produce seed, and in the vigour of their underground growth, which makes their uprooting a matter of difficulty. Partial uprooting may indeed, in the case of the perennial species, increase the mischief, for each fragment left behind may grow into a distinct plant. Annual species might be kept in check were they cut down before the flowers appear, but unless all the cultivators in a particular district co-operate the efforts of individuals are of little avail. The Globe Artichoke and Cardoon are very near allies of the thistles. The Safflower, Carthamus, another thistle, yields ...

THISTLEWOOD CONSPIRACY, or Cato Street Conspiracy, a plot formed in 1820 to murder Lord Castlereagh and other ministers of the British crown, and to seize the Bank and Mansion-House and proclaim a provisional government. Its chief instigator was Arthur Thistle wood, or properly Thistlewaite, born in 1770, the son of a civil engineer in Lincolnshire, who had held a commission in the militia and afterwards in the line in the West Indies. In America and in France he had imbibed revolutionary views, and, having lost his wife’s fortune in speculation and on the turf, had planned the desperate scheme probably for his own benefit as well as the good of the nation. The intention was to murder the ministers in the house of the earl of Harrowby in Mansfield Street on the evening of the 23d February. For this purpose between twenty and thirty men assembled in a stable in Cato Street, Edgeware Road, but while they were arming themselves they were pounced upon by the police, and a large number captured, though the majority, including Thistlewood, escaped. A reward of £1000 having been offered for Thistlewood, he was arrested next day at 10 White Street. After a trial Thistlewood and four others were executed on the 1st May, while five were transported. On being asked on the scaffold if he repented, Thistle wood replied, “No, not at all; I shall soon know the last grand secret.”

See the Trials of Arthur Thistlewood, James Ings, John Thomas Brunt, Richard Tidd, William Davidson, and others at the Session of the Old Bailey 17-28 April 1820, 2 vols., 1820; and the Gentleman’s Magazine for the same year.