BKACTS AND FLORAL LEAVES. 9 1 



it had been partly split open and spread out. The same pecu- 

 liarity is carried to a greater extent in the florets of dande- 

 lion and the ray florets of daisy. The strap-shaped limb in the 

 former case has five teeth at its termination, the latter only three 

 (cf. fig. 44). The surface of the corolla may be glabrous or 

 present hair structures or hair-like outgrowths. Its texture is 

 usually delicate, corresponding with its deciduous nature. The 

 colour may be simple, or streakings and mottlings may occur ; 

 bright tints are the rule. 



Structure. — Petals (and petaloid sepals) are covered on either 

 side by a delicate epidermis. Internally they are made up of 

 one or more layers of spongy parenchyma (cf. p. 65), traversed 

 by delicate vascular bundles, which, as in the foliage leaf, give a 

 veined appearance. The colours of flowers are due to pigments 

 contained in the epidermal cells. Blue and red are dissolved 

 in the cell-sap, as in larkspur and rose. Yellow and orange are 

 usually contained in variously shaped colour bodies, e.g., in Indian- 

 cress (garden nasturtium), where a large number are found in 

 each cell. 



