PEANUT 203 



also grown extensively for the same purpose ; the scarlet runner 

 (P. mulliflorus) is an interesting ornamental. 



Peas. The common garden pea (Pisum sativum) is well 

 known as one of our most valuable garden crops and is fre- 

 quently grown very extensively for canning. 



Clovers. The genus Trifolium includes about three hun- 

 dred species of clovers (Fig. 127), many of which are num- 

 bered among our most important agricultural crops. 



The most important clovers are the red clover (Trifolium 

 pratense L.) the mammoth clover (T. medium), the white 

 clover (T. repens), the alsike or Swedish clover (T. hy- 

 bridum) and the crimson or scarlet clover (T. incamatum). 



The term clover is also often applied to other genera, such 

 as the alfalfa (Medicago sativa) (Fig. 127), the common yellow 

 clover or trefoil (M. lupulina), the bur clover (M. denticulata) , 

 the sweet clovers (Melilotus alba, M. officinalis), the bush or 

 Japan clover (Lespedeza striata). 



Peanut. This family also includes the peanut (Arachis 

 hypogcea) (Fig. 128), licorice plant (Glycyrrhiza glabra), the 

 indigo plant (Indigo f era tinctoria) and many other plants which 

 are valuable as forest trees, field crops, drug plants, etc. 



The peunut has a peculiar habit of sending down a long 

 flower stem to thrust tRe young seed into the mellow soil near 

 the roots. This occurs just after pollination. The pod develops 

 and ripens under ground. The crop is grown for forage as well 

 as for the peanuts themselves. There are chiefly two types of 

 peanuts commercially grown for human use : the large Virginia 

 type and the small Spanish type. The latter is commonly used 

 in candies, for making peanut) butter, and for extracting oil. 



The garden and field crops are very generally grown from 

 the seeds, and the production of the commercial supply is a very 

 important industry. Great care should be exercised to guar- 

 antee seeds true to name and free from weed seeds. 



