Distinguishing Features: The smooth fruits and the beautiful red flowers distinguish this species from other members of the genus in Illinois.
OHIO BUCKEYE
Aesculus glabra Willd.
Growth Form: Medium tree to 55 feet tall; trunk diameter up to 15 inches; crown broadly rounded.
Bark: Gray to pale gray, deeply furrowed and roughened when mature.
Twigs: Stout, pale brown, smooth; leaf scars opposite, triangular, with 3 groups of bundle traces.
Buds: Ovoid, pointed, reddish-brown to yellowish, up to ⅔ inch long, not hairy, not sticky.
Leaves: Opposite, palmately compound, with 5 or 7 leaflets; leaflets obovate to oblanceolate, long-pointed at the tip, tapering to the base, up to 6 inches long, less than half as wide, toothed along the edges, green and smooth on the upper surface, green or much whitened on the lower surface.
Flowers: Numerous, yellow-green, in large clusters sometimes nearly 1 foot long, appearing in April and May, the petals of each flower of different lengths.
Fruit: Prickly, spherical or nearly so, up to 1½ inch in diameter, pale brown, containing 1 large, smooth and shiny seed.