BAIRD &TATLOCK (LONDON) LTD. 



AipctuU 



/i. t- 



t- 



- 



5732 



5732 r Collection of Weed Seeds as found in commercial samples of grass and clover seeds, 

 mounted and arranged by Professor T. Percival, M.A., University College, Reading. 

 Each set contains 200 species in two cases complete . . . . . . ..50 



(See pages 1041-1042.) 

 Seeds of Weeds found in commercial samples of Grass and Clover Seeds. 



1. The determination of the amount of the impurities in samples of grass and clover seeds is of considerable importance 

 seedsmen and fanners since the worthless impurities have to be paid for at the same rate as the good seed. 



2. In addition to the financial question involved in thus buying useless material there is another and more serious questio 

 connected with seed impurities, namely, the distribution of weeds. 



It is practically impossible to harvest the seeds of any crop without obtaining weed seeds with them, and even it 

 samples, which are usually collected by hand from wild plants, the seeds of weeds are always found. 



Troublesome pests of cultivated land have been, and are being, spread continually in all parts of the world through 

 the use of impure samples. Some of them, such as dodder, thistles, and charlock are more dangerous than others on 

 account of the great difficulty of completely eradicating them when once established, but all are objectionable. 



The present collection has been made and issued with a view of providing seedsmen, farmers, and students in colleges 

 and schools of agriculture with specimens of the chief weed seeds found in commercial samples of grass and clover seeds, 

 both of British and foreign origin. 



3. The various species of weeds present in commercial samples of farm seeds very frequently give a clue to the country of 

 origin of the samples. The collection is intended to be of service also from this point of view. 



A number of common European weeds, such as Ranunculus acris, Neslea paniculata, Thlaspi arvense, Camelina 

 saliva, Matricaria inodora, Rumex crispus, Sonchus oleraceus, and many others have been transported and established 

 among the clover and grass crops of the colonies and many parts of the American continent ; a few native American 

 weeds also have found a home in Southern Europe. On account of these facts the presence of such species in samples 

 cannot be used as evidence of the source of origin of the latter. . 



Certain species, however, may be considered as characteristic of certain countries only, being rarely or never found 

 except in samples of seeds grown in those countries. For example : 



(a) In North American samples these seeds are characteristic Nos. 25, 82, 83, 122, 130, 131, 145, 146, 169, 170, 

 192, 195- 



(fc) Nos. 124, 126, are indicative of South America. 



(c) Characteristic of Russian and Eastern European samples are Nos. 6, 7, 15, 21, 31, 45, 56, 75, 86, 101, 156. 



(d) Mid-European samples usually contain Nos. 7, 10, 14, 19, 23, 30, 33, 52, 64, 65, 70, 87, 97, 99, 152, 153, 154, 167- 



(e) Nos. I, 59, 76, in, 155, are found chiefly in samples from Southern Europe. 



CROSS STREET HATTOTST GARDE1ST, E-C 



1040 



