CHAPTER XV 



THE DEVELOPMENT AND MORPHOLOGY OF THE FLOWER 



The Development of the Flower. The young flower 

 buds appear on the stem as rounded outgrowths, and if a series 

 of these is examined by cutting transverse sections through 

 them, the order of development of the floral whorls can be ascer- 

 tained. If a series of flower buds of different ages is examined 

 from the inflorescence of the Wallflower, the very young bud 

 will show the calyx just appearing. The first sepal to appear is 

 the anterior one, then the two lateral ones are developed, and 

 last of all \\\t posterior one. In a little older bud the corolla will 

 be found as four little projections just within the sepals, and 

 alternating with them. All four petals appear at once. In 

 buds a little older still the stamens will be seen inside the 

 corolla. The order of the appearance of the stamens is as 

 follows : 



i. The anterior pair of long stamens appear first. 



2. The lateral pair of short stamens next. 



3. The posterior pair of long stamens last. 



The pistil is the last floral organ to appear ; the two carpels 

 arise together, and can be seen as small projections in the centre 

 of the bud. 



The order of the development of the floral whorls can be far 

 better made out in those flowers which are closely associated in 

 large numbers in inflorescences, like the capitulum or head, 

 (p. 1 68). Thus, in the young inflorescence of the Daisy or the 

 Sunflower, nearly all the stages of development can be seen 

 in a single section. If a young capitulum of the Daisy is 

 examined with a hand-lens, the youngest flowers can be seen 



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