28 THE MONTHLY BULLETIN. 



ton reports several species of Centaurea in his "Agricultural Botany," 

 published in New York in 1847, his yellow star thistle variety being 

 called Centaurea calcitrapa. At this time the thistles were spread over 

 parts of New England and south to the Virginias. 



The earliest records of the flora of California report star thistle around 

 San Francisco Bay, evidently brought here by the early settlers. The 

 Botanical Survey of California, published in 1880, reports it also as 

 appearing in Sonoma County. Prom that time to date it has spread 

 with ever increasing rapidity. 



METHODS OF DISSEMINATION. 



Yellow star thistle is spread by seed only, as it is an annual plant. 

 This seed is very prolific and of high germinating quality. Seed will 

 live in the ground for three or four years and germinate readily when 

 turned to the surface. The seed is a common impurity in alfalfa and 

 other agricultural seeds. It is found in baled hay, in straw packing 

 materials, and in sweepings from grain and stock cars. It is transported 

 by the wind, by traveling stock, by the annual overflow of streams, in 

 irrigating ditches, and along rights of way. Even the birds carry seeds. 



CONTROL. 



As stated before sow clean seed and demand clean hay — nothing will 

 so soon bring about a change for the better in our agricultural practice 

 as this drastic demand. In Sacramento, this winter, a man made the 

 statement in public that his hay the past season contained fully 50 per 

 cent yellow star thistle, and that he had buyers who were eager to take 

 it off his hands at the top of market price. It does not seem possible 

 that farmers could be so dull and thoughtless as to buy such stuff. The 

 purchasers must have been big wholesale men, but nevertheless much 

 of that hay and more of its like is going back to the farm every day. 



Under ordinary conditions it is not a difficult matter to control yellow 

 star thistle. Stockyards and sidings where hay or stock cars are cleaned 

 should be watched, and no thistles should be allowed to grow. This can 

 easily be handled by monthly inspection. Traveling stock should be 

 confined to certain stated highways and road supervisors should keep 

 these, and all other roads and highways, free from weed pests. How 

 it is done is of little consequence, as long as it is done. As a general 

 rule mowing twice during the summer and burning the brush will be 

 found the most effective method. The state highway commission has 

 undertaken this method of weed removal with great success. Roadsides 

 and waste places might be harrowed some time during the fall and 

 seeded to sod forming grasses. These can be broadcasted at small 

 expense and will not only serve to keep the thistles down, but will also 

 supply good pasturage for the following year. Railroads and other 

 owners of rights of way should be required to keep these places clean. 

 It has been the writer's experience that the railroads are ready and 

 willing to keep their rights of way free from noxious pests when they 

 are shown the necessity for such work. 



On waste land as well as on cultivated lands there should be one 

 object in regard to yellow star thistle control, which should be perfectly 

 clear: try wherever possible to prevent plants from going to seed. Mow 



