White Ash
Fraxinus americana · Oleaceae · Deciduous
Ash is one of the few trees with opposite compound leaves, which makes it easy once you check both characters together. It is also in serious trouble: the emerald ash borer has killed hundreds of millions of ash trees across North America, and dead standing ash is now a common sight.
Quick facts
- Arrangement
- opposite
- Leaf
- Compound leaves with five to nine leaflets on a single stalk, paler and often whitish underneath.
- Bark
- Grey with a tight, regular diamond lattice of interlacing ridges — one of the most recognisable barks in North America.
- Fruit
- Single winged samaras in dense hanging clusters, like paddles.
- Height
- 50–80 ft
How to confirm it
- Opposite AND compound — very few trees are both, which is why this combination identifies ash quickly.
- Bark in a tight regular diamond pattern.
- Leaf scars below the buds are shaped like a shallow smile or crescent.
- Look for D-shaped exit holes and woodpecker damage — signs of emerald ash borer.
What it is confused with
One observation settles each of these.
Walnut leaves are alternate, not opposite, and have far more leaflets. Check arrangement first.
Boxelder is an opposite-compound maple with only three to five leaflets and green twigs.
Where it grows
Eastern and central North America, though declining sharply due to emerald ash borer.
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.