126 THE BOOK OF NATURE STUDY 



the flower. The bases of the sepals are prolonged backwards 

 as short flaps. The five petals alternate in position with the 

 sepals, so that one stands in the middle line in front, while a petal 

 stands to either side and two form the back of the flower (Fig. 63). 

 The petal in front is the largest. It is produced backwards as 

 a hollow sac or spur, which projects between the two anterior 

 sepals, and lies beneath the flower-stalk (Fig. 64, A). The spur 

 is slightly flattened from side to side. This petal, the free margin 

 of which is slightly notched, forms a lower lip to the flower. The 

 lateral petals widen out from the narrow stalk-like basal part 

 and form the sides of the flower. Each has a small tuft of white 

 hairs about half-way up on its inner face ; the use of these will 

 be apparent later. The two petals at the back of the flower 



are narrower, and 

 bend backwards when 

 the flower has opened. 

 All the petals are 

 coloured a beautiful 

 violet blue, which is 

 paler near the base 

 A and deeper in the 



FlG. 64. Sweet Violet. A, flower cut in half ; B, stamens expanded portions 

 and pistil after removal of the sepals and petals. _* - 



(After Baillon.) The VemS f the 



petals, especially of 



the one in front, are more deeply coloured, and form a system 

 of lines converging into the opening of the flower. 



There are five stamens alternating in position with the petals. 

 The form of the stamens will be best studied if the sepals and 

 petals are carefully removed from a flower (Fig. 64, B), but their 

 relation to the corolla must be studied in an uninjured flower. 

 The stamens have extremely short stalks, and their anthers are 

 very broad and flat. Above the anther, which has a pale yellow 

 colour, the connective is continued as a triangular orange flap. 

 The anthers stand close around the pistil, and touch by their 

 edges, as do the triangular connective flaps, the tips of which 

 bend in round the style. The stamens thus form a little box 

 around the style, and the pollen is shed into this. The two 

 lowest stamens have flat green processes springing from below 



