SPRING FLOWERS 



the corolla tube, while the stigma borne on a shorter style is out of 

 sight (Fig. 66). 



Taking a long-styled flower (Fig. 66, B) for description we find 

 it to consist of calyx, corolla, stamens, and pistil. The arrange- 

 ment of these parts is, however, greatly modified by the union 

 which has taken place between them, and the flower should be 

 contrasted in these respects with such a flower as the Buttercup 

 described above. The calyx is a pale green, tubular structure 

 with its margin prolonged into five pointed teeth. These are the 

 free tips of the five 

 sepals, which are 

 united together. 

 The calyx has five 

 ridges which con- 

 tinue down from 

 the free teeth. The 

 petals are also 

 united together to 

 form a tubular 

 corolla. Their ex- 

 panded tips are, 

 however, separate, 

 and bend almost at 

 right angles to the 

 tubular portion. 

 The five lobes thus 

 form the conspicu- 

 ous face of the flower. They will be found to alternate with 

 the teeth of the calyx. The greater part of the exposed por- 

 tion of the corolla has a pale sulphur-yellow colour, but around 

 the narrow entrance to the tube and on the base of the free lobes 

 the tint is deeper, and this makes the entrance to the tube more 

 prominent. The tubular portion is not the same width throughout, 

 but suddenly widens about half way. 



When the corolla is split open the widening is found to corres- 

 pond to the place of insertion of the stamens, which are not borne 

 on the receptacle of the flower, but are attached to the inner surface 

 of the corolla. There are five stamens, which have very short 



FlG. 66. Primrose. Diagrams of relative positions of the 

 parts in the thrum-eyed (A) and pin-eyed (B) flowers, cal, 

 calyx ; cor, corolla ; stam, stamens ; stig> stigma ; sty^ 

 style ; ov, ovary. 



