DEVELOPMENT OF PLANTS 



425 



while a corresponding growth towards evening of the basal outer 

 part of the petal bends them towards the center of the flower. 

 This growth slowly increases the size of the flowers, as may read- 

 ily be observed by comparing the freshly opened flowers of the 

 anemone, buttercup, etc., with those several days old. All these 

 features are of common occurrence in a great variety of orders. 

 The fruit of the buttercup is an akene, each carpel containing but 

 a single ovule (Figs. 305, E; 261 B). 



Fig. 306. Modifications appearing in the Ranales: A, flower of Helle- 

 borus—n, nectar glands due to modifications of stamens. B, columbine — 

 n, honey leaves due to modifications of the petals or possibly of the stamens. 



(b) Some Variations of the Order. — Many variations of this 

 simple structure appear in other members of the order. The 

 carpels may be reduced to one, as in sassafras and other groups, 

 and in the green hellebore (Fig. 306, A) they are partially fused 

 and even united with the receptacle in some water lilies, etc. 

 (flowers perigynous and epigynous). The stamens are some- 

 times few in number and they are frequently modified into nectar 

 glands and assume a variety of odd shapes (Fig. 306, A). The 

 showy nectar-bearing petals, honey leaves, of many of the genera 

 are regarded by some as modified stamens, as in the monkshood, 

 columbine, larkspur, etc. (Fig. 306, B). 



The parts of the perianth, which are more frequently in threes 

 or indefinite in number than in fives, are also subject to consider- 

 able variation. Very frequently the corolla is not developed or 



