4 THE PLANT AS A WHOLE 



They become weak with one or two seasons of flowering 

 and gradually die out. Thus red clover begins to fail after 

 the second year. Gardeners know that the best bloom of 

 hollyhock, larkspur, pink, and many other plants, is 

 secured when the plants are only two or three years old. 



13. Herbaceous perennials which die away each season 

 to bulbs or tubers, are sometimes called pseud-annuals 

 (that is, false annuals). Of such are lily, crocus, 

 onion, potato. 



At* 



5. A shrub or bush. Dogwood osier. 



14. Plants which are formally perennial may become 

 annual in a shorter -season climate ~by being killed by frost, 

 rather than by dying naturally at the end of a season of 

 growth. Such plants are called plur-annuals in the short- 

 season region. Many tropical perennials are plur-annuals 

 when grown in the north, but they are treated as true an- 

 nuals because they ripen sufficient of their crop the same 

 season in which the seeds are sown to make them worth 

 cultivating, as tomato, red pepper, castor beao. 



