Chapter Seventeen 

 FLOWERS 



A flower is a stem with variously modified leaves, crowded 

 on a short axis, which leads to sexual reproduction of the 

 species through the formation of seeds. Each part of the 

 flower (petal, stamen, etc.) is a modified leaf lacking the bud 

 at the axil which is common to leaves. The flower usually 

 stops the growth in length of that particular stem or branch 

 by destroying the terminal meristem. 



Flowers are harbingers of seeds but the plant lover sees 

 them as the culmination of a great chain of events in the life 

 of the plant. When all the conditions for a particular seed- 

 bearing plant are favorable it will bear flowers. Many 

 plants, it is true, have flowers so inconspicuous that they are 

 seldom noticed and never valued for their flowers. Grasses, 

 oaks, pigweeds, and many of the chickweeds go unnoticed 

 because their color or size fail to attract us. Plants may grow 

 in a locality for many years without flowering if some con- 

 dition is unfavorable, but most plants when fully adapted to 

 their surroundings will develop internally in such a way that 

 flower buds and flowers will appear. After many years of 

 study much of the real nature of the length of day influence, 

 described in Chapter 12 and the carbon-nitrogen ratio to be 

 explained in Chapter 23, remains a secret, but enough is 

 known to enable man to regulate at will the flowering period 

 of many of our cultivated plants. 



Some plants, such as the tulip, bear their flowers singly 

 on the end of a stalk called a peduncle; others, such as the 

 petunia, bear theirs singly at the axils of ordinary leaves. 

 Most plants, however, bear their flowers in a cluster or group 

 called the inflorescence. Most flowers grow like the larkspur 



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