Origin: Eastern North America (native in Ontario)
Ohio buckeye is a small to medium-sized tree with a broad, rounded crown and drooping branches that arch upward at the tips.Read more about Tree, Bark, Twigs
Leaves are palmately compound, with 5 - 7 stalkless leaflets.Read more about Leaves
The yellowish-green flowers are borne in tall clusters, at the tips of branches.Read more about Flowers
Fruit is round to oval, with blunt spines, spliting open into two or three sections when mature, exposing 1 or more nuts.Read more about Fruit
Ohio buckeye is a small to medium-sized deciduous tree, up to 9 - 15 m (30' - 49') tall and up to 50 cm (20") in diameter.
The crown is broad and rounded, with branches that droop then arch upward at the tips. In the absence of pruning, branches often hang low toward the ground.
Twigs are reddish-brown and hairless, with orange lenticels (pores). They have an unpleasant smell when bruised.
Terminal buds are 15 - 18 mm (about 2/3") long and oval with a pointed tip. Buds are covered with a powdery coating, unlike the sticky buds of horse-chestnut.
Each leaflet is 6-15 cm (2 1/4" - 6") long, oval, widest just above the middle, tapering to the tip, and with fine teeth on the edges.
The yellowish-green flowers are borne in tall clusters, 10 - 15 cm (4" - 6") at the tips of branches.
Individual flowers are 15 - 35 mm (2/3" - 1 1/3") across, with petals fused into a narrow tube with recurved lips from which the stamens protrude. The flowers have an unpleasant odour.
Each fruit is round to oval, 2.5 - 5 cm (1" - 2") across, with blunt spines. Green when young, they turn golden brown when mature.
When ripe, the husk of the fruit (the exterior part) splits into two or three sections exposing 1 or more nuts 20 - 35 mm (3/4" - 1 1/3") across.
Ohio buckeye is Canada's only native species of Aesculus. It is widespread in the deciduous forests of the eastern United States where it grows on floodplains and riverbanks in association with hardwood trees such as sugar maple (Acer saccharum) and American beech (Fagus grandifolia). It reaches its northern limit in extreme southwestern Ontario so its native range in Canada is very small.
Derivation of names
The Latin name Aesculus refers to an oak with edible acorns, from the Latin esca, meaning food, despite the fact that Aesculus species are not related to oaks and their fruit is not edible. The species name glabra comes from the Latin for bald or smooth. The tree is called buckeye because of the resemblance of its seeds to deer eyes. Ohio buckeye is also called fetid or stinking buckeye because of the unpleasant odor of the flowers, crushed leaves, broken twigs, or bruised bark.
Like horsechestnut (Aesculus hippocastanum), Ohio buckeyes contain a toxic alkaloid called aesculin. For this reason, none of its parts, including its seeds (nuts), should be eaten by humans, even though squirrels may be seen eating them. Because of its toxicity, many farmers in the United States have eliminated Ohio buckeye from their pastures.
Ohio buckeye is the state tree of Ohio, also known as the Buckeye State.
Ohio buckeye wood is soft and fairly weak. It has been used for pulpwood, carving, and, to a limited extent, lumber but due to declining wild populations its commercial use has decreased.
Ohio buckeye may be distinguished from the non-native horsechestnut by the buds and the leaves. Horsechestnut buds are large, shiny and sticky, while those of Ohio buckeye are smaller and covered by a dry powdery coating. Generally, horsechestnut leaves are broad above the middle with an abrupt tip and irregularly toothed margins while the leaves of Ohio buckeye are widest closer to the middle and have tapering tips and finer, more regular teeth. However some cultivated varieties of horsechestnut have leaves that are deceivingly similar to those of Ohio buckeye.
Ohio buckeye's place in Toronto's urban forest
As a tree native to southern Ontario, Ohio buckeye has become a popular choice for planting on Toronto streets, yards and parks. While there are older mature trees around the city, it is more common to see young ones.
Landscape value and potential for home planting
Ohio buckeye has a lovely form, attractive flowers and good fall colour. A small tree, it is a good choice for smaller yards, and is easy to grow from seed. Because it is at its northern limit here and its leaves emerge early in the spring, it is sometimes susceptible to frost damage.
Pests and diseases: Ohio buckeye is relatively free of pests and diseases, possibly because of its toxicity. It may be affected by a fungal leaf blotch disease, Guignardia aesculi, which produces brown spots on the leaves and may slow the trees growth.
This tree is available for planting through the City of Toronto's street tree program.
Find trees on Tree Tour maps at Canadian Tree Tours: