THE HIGHER DICOTYLEDONS. 



349 



two lateral axes (2), each of which ends in a flower and then 

 gives rise to a single axis (3), and so on. How many flowers 

 are there in each " ring" ? How do the upper " rings " differ 

 from the lower ones as to number of flowers ? 



In a flower (Fig. 141) note the almost regular calyx and 

 the very irregular (zygomorphic) corolla. The funnel-shaped 

 calyx-tube has 5 nearly equal teeth, narrow and tapering, 

 longer than the tube itself ; it persists around the fruit. The 

 corolla-tube is curved; its lowest part is cylindrical, but 



ANTHER 



LATERAL LOBE 



ANT. LOBE 



COROLLA 



OVARY 



RING OF HAIRS 

 CALYX 

 NECTARY 



Fig. 142. Sectional Elevation of Flower of White Dead-nettle. 



higher up it is dilated and also flattened from side to side, 

 while its mouth has an arched upper lip, two side-lobes, and 

 a notched lower lip which spreads out. It is obvious that one 

 of the calyx-teeth (sepals) is at the top or back of the flower, 

 and since the 5 petals alternate with the 5 sepals, the lower 

 corolla-lip represents a single petal, while the upper lip, 

 though not divided, represents the two upper petals (some 

 Labiates show this clearly). 



