150 COMPOSIT.^ 



is often called Bur Thistle, and resembles the Scottish Thistle in the dull 

 purple hue of its flowers. 



The immense number of seeds produced by all the Thistles renders them 

 very troublesome to the farmer, by spreading them with great rapidity over 

 a large extent of soil. Some years since, a Scotsman, who settled in Australia, 

 having the strong feeling of nationality common to his countrymen, took to 

 the land of his adoption the seeds of flowers which grew around his native 

 home. He sowed the Thistle seed, and he was not the only one who had an 

 abundant harvest of its plants. The fertile soil suited the intruder ; and ever 

 since, the Australian farmers have had to encounter as much difficulty in 

 eradicating the Thistle as the English or Scotch cultivator of his native 

 soil has. The steppe vegetation of the Pampas, near Buenos Ayres, 

 has been overrun in the same way by introduced plants, and bears a most 

 luxuriant growth of magnificent Thistles. Robert Brown says, that in 

 common with the horses and other domestic animals which, since the first 

 colonization of these countries in the year 1535, have spread themselves 

 widely over the steppes, European plants have also been introduced, and, 

 " having completely supplanted the endemic vegetation over extensive tracts, 

 have given the country, in many districts, from the Plata to the Cordilleras, 

 its present natural character, in the same manner as the Opuntia and Agave 

 tribe have become characteristics of the shores of the Mediterranean. In this 

 region, where at the present time horses of European origin only exist, 

 Darwin has discovered the remains of a fossil indigenous horse of the latest 

 geological period ; and exactly in the same way, together with an endemic 

 Thistle, which covers extensive tracts of the Rio de la Plata, has the European 

 Cardoon obtained possession of the soil over much wider districts. This lofty 

 growth of Thistles is, on account of its extreme density, quite impenetrable 

 by man or beast. Darwin is acquainted with no instance of an introduced 

 plant occurring in such enormous quantity ; and he found on prolonged land 

 journeys the same growth frequently recurring : he even observed it beyond 

 the Plata, and saw many square miles in Monte Video thickly covered with 

 the same Thistle." 



2. Marsh Plume Thistle (C palusfris). — Stem winged by the leaves, 

 which are pinnatifid, spiny at the edges, and rough with prickles ; involucres 

 egg-shaped, clustered ; their scales pressed close, and having a sharp point ; 

 root biennial. This is remarkable for its leafy clustered heads of flowers, 

 and for being the tallest of all our wild Thistles. It grows on field-borders, 

 especially such as are watered by a stream, or on spots where some ditch 

 stagnates near at hand. In moist soils the plant will sometimes attain the 

 height of ten feet, and even in drier places the stout hollow stem reaches the 

 height of four feet. The flowers expand in July and August ; the bracts are 

 purplish-green, the flowers purplish-lilac, sometimes white, and grow on the 

 branches at the summit of the stem. The leaves are very spiny, the spines 

 often tinged with brown ; the tender stalks of the leaves may be eaten either 

 raw or boiled. 



3. Creeping Plume Thistle (C. arvdnsis). — Leaves spinous ; involucre 

 egg-shaped, nearly smooth ; its scales broadly lanceolate, closely pressed, 

 terminating in a short spine ; root creeping, perennial. In one form the 



