PERENNIAL WEEDS 



373 



the way places which would not otherwise be reached by weeds 

 not thus equipped. 



Classification of Weeds. With respect to the length of time 

 which weeds may live, they may be classified as (1) annuals, (2) 

 biennials, and (3) perennials. 



Annual weeds start from seed each year, as none of the roots 

 or other parts live over. They develop stems, root systems, leaves 

 and flowers and then bear seeds and die. This is all within one 

 year, or perhaps one growing season. There are a few annual 

 weeds that are called winter annuals which begin their growth 

 in the fall just as wheat and other winter grain does. The winter 

 chickweed is a very common example of this. 



FIG. 260. FIG. 261. 



FIG. 2GO. Hay-field in late summer with wild carrots or Queen Anne's lace. 

 FIG. 261. The wild aster is often a bad weed in pastures and hay fields. (Productive 



Bee Keeping.) 



Biennial weeds do not develop seed until the second year of 

 their growth, but after the seed matures the whole plant dies. 

 In the case of all such biennials, the plant develops a store of 

 nourishment the first growing season. During the second growing 

 season the plant uses up this store of nourishment which aids it in 

 developing and ripening its seeds. Burdock and wild carrot 

 (Queen Anne's lace, Fig. 260) are very common biennial weeds. 



Perennial weeds are of two main types: The herbaceous 

 perennials, which die to the ground each year, but the underground 

 parts including the roots live from year to year for several or many 

 years. The other form of perennials may live above ground as 

 well as under ground for several years. These are usually more or 



