128 SILVA OF NORTH AMERICA. LEGUMINOS. 
from which they differ in their smaller number of stamens united at the base into a tube free from the 
corolla, and in their legumes which, like those of Entada and Mimosa, mostly open by the separation 
of the thin walls from the persistent thickened margins. 
The generic name, from Avo. and Adua, refers to the separation of the valves from the margins of 
the legume. 
