Northern Red Oak
Quercus rubra · Fagaceae · Deciduous · also called red oak
The red oak group is defined by bristle-tipped lobes, and northern red oak is its most widespread member. The shiny flat-topped ridges on mature bark, often described as ski trails, make it recognisable in winter without a leaf in sight.
Quick facts
- Arrangement
- alternate
- Leaf
- Seven to eleven lobes, each ending in a sharp point tipped with a fine bristle. Sinuses are shallower than a white oak's.
- Bark
- Dark grey-brown with flat-topped ridges that look like ski tracks running down the trunk — a genuinely distinctive pattern.
- Fruit
- Barrel-shaped acorn with a shallow saucer-like cap, taking two seasons to mature.
- Height
- 60–90 ft
How to confirm it
- Bristle tips at the end of each lobe — the defining red oak character.
- Bark with flat-topped shiny ridges running vertically like ski tracks.
- Acorns take two years to mature, so you see two sizes on the tree at once.
- Alternate leaves.
What it is confused with
One observation settles each of these.
Bristle tips mean red oak group; rounded lobes mean white oak group.
Pin oak has deeper, narrower sinuses and keeps dead lower branches angled sharply downward.
Where it grows
Eastern and central North America, and widely planted as a shade and street tree.
Start here: opposite or alternate?
Look at where the leaves join the twig. Are they in matched pairs directly across from each other, or staggered one after another? The vast majority of trees are alternate, so finding an opposite tree removes almost everything else in one step.
In North America, opposite-leaved trees are remembered as MAD Cap Horse: Maple, Ash, Dogwood, Caprifoliaceae (viburnums and elders), and Horse chestnut. That is very nearly the whole list.
Check partway along a healthy twig rather than at the tip, where crowding can make alternate leaves look paired. And check more than one twig.