GROWING PLANTS. 205 



live some years before they blossom, fruit, and 

 die. But generally these monocarpous plants spring 

 up, produce seed and die in a single year, when 

 they are called " annuals?^ as wheat : or they do 

 not come into flower and seed until the second year 

 and then die, as the turnip ; these are called 

 " biennials." } 



But many plants blossom and seed continually year 

 after year and so are called polycarpous* These are 

 shrubs and trees with woody stems and herbs with 

 underground stems, such as rhizomes, bulbs, etc. 

 These are commonly called ^ perennials"^ 



How long do seeds keep alive ? They vary very 

 much, but some will grow after very many years if 

 the life has not been destroyed by heat or cold or 

 other special cause. Dr. Hooker mentioned an instance 

 of an Indian bean growing after 100 years as being one 

 of the longest proved instances of seed life ; but this 

 is a very much disputed point. If, however, you are 

 ever near a place where new soil has been thrown up 

 to the surface, as in a gravel pit or railway cutting, 

 always look for any new plant, new to the neighbour- 

 hood at least, which may have sprung up from long 

 buried seed. 



So now I hope you know a little about the methods 



* See note * on page 204. 



f From the Latin " annus," a year (annual, of one year); " fa's" 

 twice and annus (biennial, of two years) ; or "per" through, and annits 

 (perennial, through or during several years). 



