Tree 10 - 20 m tall, trunk 30 cm - 0.60 m in diameter Leaves: opposite, palmately compound, stalked, with seven to nine leaflets. Flowers: showy, borne in loosely branched inflorescences (panicle), white with a yellow or red spot near the base, 20 - 30 cm long, 10 - 20 cm wide, each floret with four to five petals, the stamens longer than the petals. Fruit: a capsule enclosing one to three seeds, 5 cm in diameter, rounded, prickly, leathery. The seeds are shiny brown with a pale circular marking, large, and smooth. Bark: dark brown with orangish brown inner bark, shallowly fissured with thin irregular plates. Twigs: stout, reddish brown with tiny, white, corky, raised spots (lenticels). Terminal buds: 2 - 4 cm long, egg-shaped, very sticky, with reddish brown outer scales and yellow inner scales. Leaflets: dark green above, paler beneath, 12 -18 cm long, 3 - 6 cm wide, inversely egg-shaped with a wedge-shaped base and a pointed tip, irregularly toothed. Leaves turn brownish yellow in fall.
Similar species: Aesculus glabra typically has five leaflets, terminal buds 1.5 - 1.8 cm long, fruit 2 - 3 cm in diameter, and releases an unpleasant odor when leaves and twigs are bruised.
Flowering: late May to June
Habitat and ecology: Occasional escapes, usually seedlings, are found near mature cultivated trees. The species also occurs along mesic ravine slopes and slopes of clay ridges.
Occurence in the Chicago region: non-native
Notes: The wood of this species is use in Europe for kitchen utensils, food containers and carving into decorative objects. The seeds are poisonous.
Etymology: Aesculus is the Latin word for a species of oak with edible nuts, but was used by Linnaeus to name this genus. Hippocastanum comes fro the Latin name for horsechestnut.
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
Reported in Coulter's Catalogue as escaping from cultivation. Also reported by Andrews for Monroe County without data. It is reported as sparingly escaped in Michigan and Schaffner, in his Catalogue of Ohio Plants, says: "No specimens."
Indiana Coefficient of Conservatism: C = null, non-native
Tree to 25 m; winter-buds glutinous; lfls commonly 7(9), wedge-obovate, 1-2.5 dm, abruptly acute, irregularly serrate or biserrate, pubescent beneath when young, later glabrous; infls many-fld, ovoid-conic, 2-3 dm; cal 5-7 mm; upper and lateral pet with white rotund blade marked with red or yellow at the cordate base, on slender claws; fifth petal obovate, tapering to a broad claw, or wanting; fr echinate, 5 cm thick; 2n=40. Native of se. Europe and adj. Asia, occasionally escaped from cult. in our range. May.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.