406 



THE RANALES 



and consequently the organs of the flower, especially the sporo- 

 phvlls, are numerous and indefinite in number and spirally ar- 

 ranged. Were it not for the perianth, such a type of flower 

 would be quite as primitive as any of the preceding orders. 



(a) The Buttercup, Ranunculus. — The flower of the buttercup 

 illustrates the more characteristic features of the Ranales (Fig. 

 305, A, B). The calyx and corolla form two whorls of five 

 members each, but the sporophylls are indefinite in number and 

 spirally arranged. It is interesting to note the relationship of 

 the various parts of this simple flower and their behavior during 



Fig. 305. A common type of the Ranales, Ranunculus repens: A, habit 

 of the plant. B, early stage of flowering, the stamens clustered about the 

 stigmas. C, late stage of flowering, nearly all the stamens bent over 

 towards the petals, having discharged their spores. D, petal with nectar 

 gland at base. E, fruit consisting of numerous spirally-arranged akenes. 



the period of blooming. When the flower first opens, the anthers 

 are still closed and clustered around the receptive stigmas, afford- 

 ing a natural landing place for the insects (Fig. 305, B). Thus 

 crossing may only be effected with the spores carrried from older 

 flowers. At a later period the outermost filaments elongate, 

 curving over towards the petals, so that as their anthers discharge 

 there is little chance of autogamy (Fig. 305, C). This position 

 also brings the anther into the pathway leading to the nectar 

 gland at the base of the petal (Fig. 305, D), so that the insect 



