ANNUALS, BIENNIALS, PERENNIALS. 



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ubsorbed from the earth by the rootlets; but in both cases it tiiids its way into the 

 inner cellular structure of the leaA^es, and it is therein eheniieally prepared, or 

 digested, each of the thousands of cells in a leaf acting as a stomach. What these food 

 substances are we shall state under the headings of Eoots and Leaves. 



Plants may be grouped into sections according to the time tliey occupy in perfecting 

 themselves from seeds ; or on account of their habits and l)e]un iour under changes of 

 climate. Thus, for example : — 



Annuals are plants that grow from seeds sown in spring, and fully develop them- 

 selves within the year. Thus the whole growth cycle iFig. 4) is completed, they 

 -germinate, grow, tlower, and ripen seed during the wanner portion of thp one year. 



Examples of annuals are sweet peas, maize, and ^ 

 other cereals, peas and beans, nemophila, and (as ^i^^-^ "'-.^ 



grown) mignonette. Annuals of course gene- ^■>-f/oa-er Stem;^ 



' 5 3 ^ 



rally die after ripening their seeds. / 



Biennials are plants that may be sowai at almost ; 1 



any season in one year, but they do not flower and 



ripen seed until the succeeding year. That is to say, <4 /■'•■' at ^"'^'--;\ 

 biennials occupy the best part of two years in com- '^.^ ^ ^ 



pleting their growth cycle. The first year they save >^»' 

 up reserve stores of food, and the second year they _ ' /~V,s7^ 



utilise it in perfecting their flowers and seeds, ^ b c 



Examples of such plants amongst flowers are '-^^^'-^ole of plan. Okowth. 



-I, annual. 7-', biennial. perennial. 



Canterbury bells, honesty, sweet williams, foxgloves, 



and the evening primrose hicnnis). Biennials generally 'lie the second year 



after ripening their seeds, but do not always do so. 



Perennials are plants that live at least more than two or three, and possibly for 

 many years, and they do not die after having flowered and seeded as annuals do always, 

 and biennials do very frequently. 



Like the biennials, this group may also be divided into those that retain their 

 foliage fresh all the year (evergreens) or that shed their leaves, or die down to the 

 ground line on the approach of winter, in which case they are called herbaceous. 



Evergreen perennials are such plants as hellebores, saxifraga and megasea, arabis, 

 aubretia, violets, pansies, and others of a like nature. Ilerhaceons perennials are pasonies, 

 delphiniums, and most composite or daisy- flowered plants, such as helianthus, pyrethrum, 



