240 



NA TURE-STUD Y RE I 'IE W 



[6:8— Nov., 191* 



avoided. Most of us who have gone barefoot or played ball on 

 sandy fields have had experience with the vicious sandbur, whose 

 burs are beset with the sharpest of spines which have a way of 

 insinuating themselves where not wanted. 



As a rule, the burs are not painfully injurious, but bother- 

 some. The coarse, unsightly burdock, cocklebur, beggar-ticks, 

 etc., cling to our clothing. They get into the hair and wool of 

 animals. Horses' manes and tails are often badly matted with 

 them. The wool of sheep has to be especially combed for burs 

 before it is spun. Longhaired dogs are greatly hampered by burs- 

 in their coats and feet. The shorthaired pointer is better adapted 

 to bur-filled jungles than the setter. 



One reason for 

 the success of many 

 weeds in the com- 

 petitive struggle for 

 existence is that 

 they are provided 

 with excellent de- 

 vices for seed dis- 

 p er s a 1 — elastic,, 

 throwing stems with 

 open pods (butter- 

 print, mallein) , par- 

 achutes (dandelion, 

 thistle), wings and 

 floats (sorrel), tum- 

 bleweeds (Russian 

 "thistle")) burs 

 (burdock, cockle- 

 bur). They make 

 excellent material 

 for studying the 

 dissemination of 

 plants. 



Weeds are found in neglected back yards, vacant lots, road- 

 sides, railroad tracks, fence rows, fields and pastures, where they 

 have been blown by the wind or carried by man and other ani- 

 mals. 



Many weeds now growing in this country are not native 



seed pods of velvet leaf 

 (known also as butter print or pie marker.) 



