MORPHOLOGY OP LEAVES AND FLOWERS 



611 



Fig. 469. Strap-shaped and tubular flowers from the head of Squaw Weed 

 (Senecio). The corolla and calyx appear to arise from the top of the 

 ovary. Such a flower is epigynous and the free portion of the calyx is 

 called pappus. 



(After Thome.) 



Flowers may arise singly, as in silverweed (Potentilla anserina), 

 and are then designated as solitary. If in the axils of ordinary 

 leaves, they are axillary and solitary. 



A raceme is that indeterminate inflorescence in which the flowers 

 are stalked and arranged along the sides of a floral axis. The 

 shepherd's purse has the raceme type of inflorescence. New flowers 

 are continuously arising at the top as the floral axis elongates. 



Fig. 470. Solitary, funnel-shaped flower of field Bindweed. 

 (After Thome.) 



If the inflorescence is of the raceme type with the exception that 

 the flowers have no stalks, as in the plantain, we have the spike. 



