No. 6. DEPARTMENT OF AGRICULTURE. 271 



THE WEEDS REPRESENTED IN THE FOREIGN SEEDS. 



In the list below, only those weeds are noted which were more or 

 less common in the samples of seeds examined. Occasional seeds 

 of many other kinds of weeds were found, but never in sufficient 

 quantity to merit notice here. Every sample was carefully examined 

 and the foreign seeds removed for identification which was greatly 

 facilitated by the use of the five hundred samples of "Economic 

 Seeds" distributed by the Division of Botany of the United States 

 Department of Agriculture, supplemented by a collection of 2,000 

 samples possessed by the Pennsylvania State College. 



On the whole, the samples of farm seeds were fairly well cleaned, 

 and in the matter of purity, they were generally as high as or higher 

 than the standard fixed by the United States Department of Agri- 

 culture. None of the weed seeds found could be classed with the 

 Canada Thistle as regards their obnoxious characters. A very few 

 of them are weeds not yet known to be in Pennsylvania. 



AJsihe (Trifolium hybridum L.) Alsatian Clover. SwedhJi. Clover. 

 Cultivated for fodder. Occurs as a weed in waste places from Nova 

 Scotia to Idaho, south to New Jersey and Georgia. The seeds, which 

 resemble that of White Clover, though much darker, occurred asi an 

 impurity, particularly in the Kentucky Blue Grass seed. For lawn 

 purposes the presence of Alsike in the Blue Grass seed is objection- 

 able; but for pasture fields it ofi'ers no disadvantage. 



"Barnyard Grass (Panicum Crus-galli L.) CockspiiT Grass. A widely 

 distributed weed, found all over the United States, and was introduced 

 from Europe. It prefers rich land and is commonly found in great 

 luxuriance in and about barnyards; hence the name. The seeds 

 are large and can easily be separated from crops of agricultural 

 seeds; therefore, it is seldom present in properly cleaned seeds. 

 It was found in very small quantities only, and that in two samples 

 of Red Clover. 



BicknelVs Crane's-hill (Geranium Bicknelli Britton). A native 

 plant at present found from Maine to Southern New York. It is an 

 annual, growing 10 to 20 inches high. The seeds were present in only 

 one sample of seed and that the Crimson Clover (sample No. 133), 

 grown probably within the territory indicated above. While the 

 plant as a weed may be easily controlled, no farmer wants to pay 

 for seed that will be of no benefit to him. The seed of this? Crane's-bill 

 is much smaller than the Crimson Clover and could be easily sepa- 

 rated. 



Black Medic (Medicago Inpulina L.) Blackseed Hop Clovef)\ Meli- 

 lot^lrefoil. An annual clover-like plant introduced from Europe 

 and widely distributed as a weed. The seeds occurred as an impurity 



