440 THE RANALES 



flower becomes nearly or quite erect and turned towards the 

 light, so that it is in a position from which the insect will naturally 

 come. The opening of the flower is due to a growth in the morn- 

 ing of the basal, inner portion of the petals thus bending them 

 away from the center of the flower and thus effecting the opening ; 

 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). 



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

 simple structure appear in other members of the order. The 



n 



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

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

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



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

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

 pounded 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). 



