White Black Red Oak Acorn Identification
Here is a quickie field identification guide for three common dry soil and ridge top oak species (White, Black, and Red) in Pennsylvania, New Jersey, New York, and Maryland. Distinguishing features are listed below the picture. Click to see a large format picture in a new window for a closeup view.
Quercus alba (White Oak) – Large stately tree in dry soils. Acorns 0.5″-0.75″ elongated with a distinctive sheen, almost glossy. Chestnut color. Caps have tortoise-like plates that extend about one third of the length of the acorn. Typically sprouts in the fall if left laying on the ground.
Quercus velutina (Black Oak) – Tall tree in dry soils. Acorns about 0.38″-0.5″ long and wide. Dark brown color with distinctive vertical black striping on the acorn. Caps have overlapping elongated shingles that extend one half to three quarters of the length of the acorn and splay out at the ends. Prominent tip on the acorn.
Quercus rubra (Red Oak) – Tall tree in many conditions. Acorns about 0.5″ long and wide and colored light tan and have a matte finish. Cap has tightly appressed shingles that terminate at a clean edge about a third of the length of the acorn.