42 
WAYSIDE AND WOODLAND TREES. 
and are dependent on the wind for the transfer of pollen. The 
fruit is an oblong samara, about an inch long. This consists of 
a single seed in the centre, invested by a thin envelope, which is 
extended all round as a light membranous wing, which gives 
it buoyancy and enables it to float through the air to a little 
distance. These seeds are not produced until about the 
thirtieth year of the tree’s life, and though they are ripened 
almost annually thereafter, good crops are biennial or triennial 
only. It has often been stated that the Wych Elm does not 
send up suckers, but it does, though not invariably ; it does 
so chiefly as the result of root-pruning or some other check to 
the extension of the root-system. 
