American Chestnut
Castanea dentata (Marsh.) Borkh.
Fagaceae: Beech Family
Châtaignier d'Amérique
Range:
Once a dominant tree in broadleaf forests of southern Ontario and the eastern U.S.
Now rare due to chestnut blight (Endothia parasitica).
Survives mostly as stump sprouts, rarely reaching full size.
Leaves:
Deciduous, alternate, simple.
15-28 cm long, tapering at both ends, short-stalked.
Yellowish-green.
Straight, parallel veins (15-20 per side), each leading to a prominent tooth that extends into a short, curved bristle.
Buds:
Ovoid, 5-8 mm long, pointed, greenish-brown.
2 or 3 hairless scales.
End bud similar to lateral buds.
Leaf scars semi-oval, slightly raised, with numerous vein scars.
Twigs:
Stout, shiny, reddish-brown.
Numerous light-colored lenticels.
Pith 5-pointed.
Flowers:
Monoecious (pollen and seed flowers on the same tree).
Pollen flowers: short-stalked, semi-erect catkins (12-20 cm long), in leaf axils.
Seed flowers: solitary or in clusters of 2-3, at the base of some pollen catkins.
Bloom after leaves have nearly fully grown.
Fruits:
Edible nuts, in small clusters of 1-5 within a spiny bur-like husk (5-8 cm across) that splits into 4 parts.
Each nut: ovoid, flat on one side, pointed, dull brown, smooth.
Seedlings:
Cotyledons white, fleshy, remaining in the seed coat under the surface.
Vegetative Reproduction:
Primarily by stump sprouts.
Bark:
Smooth, dark brown when young.
Develops broad, flat-topped ridges with age.
Wood:
Moderately hard and strong.
Oak-like grain on tangential face, straight-grained.
Reddish-brown, very decay-resistant.
Ring-porous, with large, easily visible pores.
Prominent annual rings.
Rays very small.
Size and Form:
Before the blight, grew up to 35 m tall and 100 cm in diameter.
Now rarely exceeds 10 m.
Some specimens over 50 cm in diameter still exist in Ontario.
Habitat:
Adaptable to various sites.
Prefers well-drained sands and gravels.
Typically found mixed with other broadleaf trees.
Notes:
Chestnut blight likely entered North America in 1904 from imported Asian stock.
Most trees have died, but stump sprouts can reach pole size before succumbing to blight.
Attempts at breeding for disease resistance have failed.
Introduction of a less virulent blight strain may help trees survive.
Historically valuable for its durable wood.
Chinese Chestnut (Castanea mollissima)
Native to China and Korea.
Hardy to zones CA6, NA4.
Similar to American chestnut but somewhat resistant to chestnut blight.
Quick Recognition:
Leaves alternate, long, narrow, with straight veins and large bristle-tipped teeth.
Fruit a large bur.

The American Chestnut is a tragic loss—it was once called the "Redwood of the East" for how massive and dominant it was in forests. Have you ever seen a surviving one in the wild? Most people only find the stump sprouts, but a few lucky trees have made it longer than expected.