Fre. 164. A group of leaves and acorns illustrating some of the differences 
between six species of oak (Quercus) 
i, the white oak (Q. alba); B, the red oak (Q. rubra); C, the bur oak (Q. macro- 
carpa); D, the black oak (Q. velutina) ; E, the blackjack oak (Q. marylandica) ; 
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 
195 
