Iowa State Tree

Iowa State Tree

Bur Oak

Fagaceae Quercus macrocarpa Oak Burr Quercus macrocarpa
Alternate, simple, 5 to 8 inches long, oblong in shape with 7 to 11 bristle-tipped


Staminate flowers borne on catkins. Pistillate flowers borne on spikes.
Appears with the leaves in April or May.


Acorns are 3/4 to 1 inch long and nearly round. The cap is flat and
thick, covering about 1/4 of the acorn. Matures in 2 years, ripens August to late October.


Quite stout, red-brown and glabrous. Terminal buds are multiple, quite
large, ovoid, and covered with red-brown, mostly hairless scales.


On young stems, smooth. Older bark develops wide, flat-topped ridges
and shallow furrows. The shallow furrows form a pattern resembling ski tracts.


A medium-sized to large tree that develops a short trunk and round crown when open grown, straight with a clear bole when grown with competition.

Oak Burr Quercus macrocarpa
Copyright 2019 Virginia Tech Dept. of Forest Resources and Environmental
Conservation; Photos and text by: John Seiler, Edward Jensen,
Alex Niemiera, and John Peterson;Silvics reprinted from Ag
Handbook 654; range map source information