LENGTH OF LIFE 



germination. It ends with death — that is, when no life is 

 left in any part of the plant, and only the seed or spore 

 remains to perpetuate the kind. In a bulbous plant, as a 

 lily or an onion, the generation does not end until the bulb 

 dies, even though the top is dead. 



10. When the generation is of only one season's duration, 

 the plant is said to be annual. 



When it is of two seasons, it 

 is biennial. Biennials usually 

 bloom the second year. When 

 of three or more seasons, the 

 plant is perennial. Examples 

 of annuals are pigweed, bean, 

 pea, garden sunflower, maize; 

 of biennials, evening primrose, 

 mullein, teasel, parsnip, carrot; 

 of perennials, dock, meadow 

 grass, alfalfa, cat-tail, and all 

 shrubs and trees. The bien- 

 nial and perennial weeds 

 are the most difficult to 

 eradicate. 



11. Duration of the 

 Plant Body. — Plant struc- 

 tures that are more or less 

 soft and that die at the 

 close of the season are said 

 to be herbaceous, in contradistinction to being ligneous or 

 woody. A plant that is herbaceous to the ground is called 

 an herb; but an herb may have a woody or perennial root, 

 in which case it is called an herbaceous perennial. Annual 

 plants are classed as herbs. Examples of herbaceous per- 

 ennials are buttercup, bleeding-heart, violet, water-lily, 

 many grasses, dock, dandelion, goldenrod, asparagus, 

 rhubarb, many wild sunflowers (Figs. 3, 4). 



