184 



ASH-KEYS. 



[CH. XIV 



The corolla has fallen off and the pappus or hair-like 

 calyx has developed into a delicate crown separated from 

 the ovary by a stalk. The crown of hairs serves as a 

 parachute which buoys up the fruit and enables it to float 

 on the wind to great distances. 



The fruits of the Ash (Fraxinus) and of the Sycamore 

 (Acer pseudoplatanus) are also wind-distributed, although 

 not so effectively as the " clocks " of the dandelion. 



The fruits or " keys " of the ash are familiar to every- 

 one, and are seen in the summer and autumn growing in 



FIG. 85. 



FRUIT OF THE ASH. 



THE SAME OPENED, showing a single ovule developing into the seed 

 while the remaining three ovules do not develop further. 

 TRANSVERSE SECTION OP THE LOWER PART OF A, showing the cavity of 

 the ovary, and the vascular bundles of the two carpels. 

 A SMALL PART OF (7, more highly magnified, showing the thick-walled 

 cells next the inner surface. 



