FOREWORD. 



This bulletin is a companion to number 260, published March, 1910, 

 which was entitled Seeds of Michigan Weeds, and the two can profitably 

 be studied together. 



The aim has been not to repeat much that has been so recently pub- 

 lished. 



Very nearly all the drawings were made by F. Schuyler Mathews of 

 Cambridge, Massachusetts. Figures 2, 3, 4, 4a, 8, 10, 11, 12, 16, 19, 20, 

 are taken from Bulletins by the U. S. Dcpt. of Agriculture. 



I am indebted to Dr. B. L. Robinson and M. L. Fernald of the Gray 

 Herbarium of Harvard University for valuable hints and access to 

 numerous herbarium specimens. 



In all the plans made for extermination of weeds do not forget that 

 when buried in the soil, a portion of the seeds of many weeds will re- 

 tain their vitality for 30 years at least. 



Two numbers are given to most of the illustrations, the one in paren- 

 thesis is the number corresponding to that of the cut in bulletin 260. 



In the study of weeds as in the study of other plants it is well to 

 group them according to some of their points of agreement. 



In this treatise, I have given a brief popular account of each family 

 that contains one or more weeds here illustrated. 



Placing these cuts one to three to the page according to shape and 

 size makes it impossible in many cases to arrange the species in approved 

 sequence. In spelling and capitals I follow Gray's Manual, 7th Edi- 

 tion. 



In the back part of the bulletin are duplicate copies of the decimal 

 scale that any one can cut out and use for a measure, though these figures 

 are not all natural size. 



W. J. BEAL. 



