FIG. 104. A group of leaves and acorns illustrating some of the differences 

 between six species of oak (Quercua) 



A, the white oak (Q. alba) B, the red oak (Q. rubra) ; r, the bur oak (Q. macro- 



carpa) ; I), the black oak (Q. velntina) ; E, the blackjack oak (Q. inarylandica) ; 



F , the live oak (Q. virginiana). The acorns are about three fourths natural size 



and the leaves less than one half natural size. Modified from R. B. Hough 



196 



