214 Classification of the Oaks. 



2. Seeds maturing the second year : 



Quercus chrysolepis (v acciniifolici) , Canon live oak. 



Palmerii, Palmer's dwarf oak. 

 " tomentella. 



B. MELANOBALANUS (Black Oaks.) 



1. Seeds maturing annually ; leaves persistent : 



Quercus Emoryi, Emory's oak. 



agrifolia, Field oak. 

 " pumila, Dwarf oak. 

 " hypoleuca. 



2. Seeds maturing the second year : 

 (a.) Leaves deciduous. 



Quercus rubra, Black oak ; Red-oak. 



" coccinea 1 (tinctoria), Scarlet-oak. 



" Kettoggii, California black-oak. 

 falcata, Spanish-oak. 



" Catesbaei, Catesby's oak. 



" ilicifolia, Black scrub-oak. 



" palustris, Pin-oak. 



" Georgiana. 



" aquatica, Water-oak. 



" laurifolia, Water-oak. 



" nigra, Black-jack. 



" cinerea, Upland willow-oak. 



" imbricaria, Shingle -oak. 



" phellos, Willow-oak. 

 (6.) Leaves persistent. 



Quercus Wislizeni, California live-oak. 



' ' myrtifolia. 



One other, the California chestnut oak (Q. densiflora) , can be 

 classed with neither. 



854. Hybrids are occasionally noticed in the oaks, from the cross- 

 fertilization of species, but not outside of the group to which the 

 species belong. The differences between white oaks and black oaks 

 are too great to admit of this crossing, and they have been more 

 frequently noticed in the black oaks. The following black oaks, 



1 The Q. coccinea and Q. tinctoria are, by some botanists, made separate 

 species. 



