A KEY TO THE GROUPS OF OAKS
A. Acorns, annual; bark usually pale; leaves with rounded lobes, not
spiny-pointed.
The White Oak Group.
AA. Acorns, biennial; bark usually dark; leaves with spiny-pointed
lobes.
The Black Oak Group.
Trees Every Child Should Know: Easy Tree Studies for All Seasons of the Year · 第 81 / 89 题