Ohio buckeye (Aesculus glabra) , the state tree of Ohio, is found primarily as an understory tree in the western half of Ohio, where the soils are more alkaline in pH. However, it is scattered throughout the eastern half of the state, except in extreme northeastern and extreme southeastern Ohio. Its lightweight wood is used in the production of artificial limbs. A native of the Midwestern and Great Plains states, trees found in the open may reach 60 feet tall by 30 feet wide, but as a native understory it is often half that size. As a member of the horsechestnut family, it is related to other horsechestnuts and buckeyes, including man-made hybrids between the species. Ohio buckeye prefers moist, well-drained soils of variable pH that are rich and deep, in partially sunny to partially shaded conditions. It adapts to average soils that are occasionally dry, but moderate to heavy leaf scorch will develop by mid-summer, especially when sited in full sun. Ohio buckeye prefers shady conditions in its youth but grows in full sun to full shade from youth through maturity and is found in zones 4 to 7. Ohio buckeye often suffers from leaf blotch, leaf scorch, and powdery mildew on its foliage, which also plagues the closely related horsechestnut (but not yellow buckeye). As such, Ohio buckeye should be planted in partially shaded to fully shaded conditions for best foliage health in mid- to late summer. However, it should be planted in partial sun to full sun for best floral and nut production (preferably with supplemental irrigation during summer). Ohio buckeye has opposite, palmately compound leaves that are clean and medium green in spring. Each leaf has five leaflets, and they are a little bit smaller and less wide overall as compared to yellow buckeye, with which they may be easily confused. Also, leaflets of Ohio buckeye are not fused at their bases like those of horsechestnut. Unfortunately, leaves of Ohio buckeye become very prone to scorching, discoloration, and foliar diseases by mid-summer, as does horsechestnut. As a result, Ohio buckeye and horsechestnut have a brown, fall-like appearance to their foliaged canopy by mid-summer and may be nearly defoliated by late summer. A comparison of the size and shape of a leaflet of Ohio buckeye with horsechestnut shows obvious differences. Ohio buckeye is much smaller, elliptical (widest near the center of the leaflet), with a drawn-out and pointed tip. Horsechestnut is much larger, obovate (widest near the tip), but with a blunt tip that is almost absent. Ohio buckeye has showy yellow-green flowers in early spring, emerging just before or with the foliage. Their stamens (pollen-bearing structures) are long and extend far beyond the petals, whereas the similar-looking flowers of yellow buckeye have shorter stamens that stay within the petals. Fruits of Ohio buckeye usually contain one seed (or nut) enclosed in a slightly spiny, golden-brown husk. Fruits may occur singly or in clusters, enlarging and becoming more obvious by mid- to late summer. The dormant buds of Ohio buckeye resemble those of yellow buckeye, but upon close inspection they have overlapping scales that flare slightly at their edges, a very subtle trait that is hard to determine in many cases. However, they in no way come close to the size, shininess, and stickiness of the winter buds of horsechestnut. The bark of Ohio buckeye is somewhat variable but becomes broken into subtle flaky ridges with maturity. It is light gray to light brown and develops more prominent fissures and long plates with age. However, it tends not to have the rectangular, platy appearance of the bark of yellow buckeye or horsechestnut.