14 THE CANADA THISTLE. 



* ' The plant seems to be particularly a railway weed. It has appeared 

 first along the railways in sixteen of the twenty-one States and Terri- 

 tories in which it has been introduced. In nearly all the States where 

 it is now found its wide circulation has been chiefly by railways, in 

 spite of the fact that railway companies have generally done more than 

 all other parties to combat it." (Yearbook, 1896.) 



CANADA THISTLE. 



The Canada thistle, so called, is altogether a different plant from the 

 Russian stranger, and is a true thistle. This pest is known by various 

 local names, as "cursed thistle," "corn thistle," "hard thistle," and 

 "creeping thistle," but by whatever name called it is always the same 

 costly, unconquerable enemy of the farmer. This plant, although 

 known as the Canada thistle, is a native of Europe and reached our 

 country by Newfoundland, from which point of entry it has now 

 spread west to Nebraska and south beyond Virginia. Like the great 

 pests of our California farmers, the dreaded morning-glory and the 

 Johnson-grass, it creeps through the soil by means of root-stocks and it 

 is almost, impossible to eradicate it, as every piece of root left in the 

 ground forms a new plant, and the more it is cut up the more it thrives. 



The following description of the thistle is given by Prof. Moses Craig, 

 Botanist of the Oregon Agricultural Experiment Station: 



"This plant differs from the common Bull thistle, for which it is 

 often mistaken, in its slenderer, wingless stem and branches, in the thin, 

 narrow (% to % inch), curled and more deeply cut leaves, less rigid 

 prickles, and smaller flower heads which are about half an inch in 

 diameter. It is more difficult to destroy than the common thistle, as it 

 is a perennial, spreading by long underground stems, which penetrate 

 deeply into the soil, often below the reach of the plow. These rhizomes 

 extend horizontally in all directions, and being furnished with buds 

 send branches to the surface, where a tuft of leaves is first produced, 

 followed later by aerial stems, which bear flowers and seed. These die 

 down to the ground every fall, but in the spring the rhizomes again send 

 up numerous branches, which soon cover the ground, the plants spread- 

 ing with surprising rapidity from year to year. 



"This 'Cursed Thistle' is also propagated by seeds, which, supported 

 by the downy pappus, are often carried long distances by the wind. 

 Like most of our troublesome weeds it was introduced from Europe 

 and has now become permanently established in this country. It has 

 been reported from nine counties in Oregon, where fortunately it is 

 not abundant. 



"Cnicus arvensis, Hoffra. Fl. Germ. IV 180 Perennial and spreading by creeping 

 root-stalks a foot or two high, corymbosely branching, usually glabrate and green; 



