Native species of buckeye are deciduous large shrubs or small trees native to North America and Eurasia. They are in the soapberry family, Sapindaceae , that also includes maple and lychee. Native species grow up to 79′ tall and have opposite, palmately compound leaves with 5-7 leaflets, occasionally 9. The leaflets have toothed margins and turn yellow to orange or bronze in the fall. Panicles of white, pink, red, or yellow, flowers appear from spring into early summer. The fruit that follows is a capsule containing 1-3 seeds. All parts of the plant are moderately toxic.
Buckeyes like full sun to partial shade and average, medium moist, well-drained soil in USDA Hardiness zones 6-9 but hardiness varies greatly among the species. Plants are generally healthy but may be damaged by leaf blotch, leaf scorch, powdery mildew and more. Propagation is by seed and cuttings.
The genus name, Aesculus, is the classical Latin name for a kind of oak tree.
Photo Credit: Wikimedia
The environmental conditions of the Southwest have resulted in at least two species of buckeye native to the Southwest but they may be native to other areas of the US too. The buckeye described here are native to at least two of the states in the Southwest.
Ohio Buckeye (Aesculus glabra)
This small to medium sized deciduous tree is low-branched and has a broad oval-rounded crown. The palmately compound leaves have 5 elliptic to obovate leaflets, that are 3-6″ long. Fall foliage is usually yellow, but may become orange-red or reddish-brown. Terminal panicles of greenish yellow flowers appear in mid to late spring. The panicles are 4-7″ long, and the flowers are 1″ long, and 4-petaled with the stamens longer than the corolla. The fruit that follows is a small spherical capsule with a prickly or warty covering and contains one to three seeds. The flowers, bark, and stems, have an unpleasant odor when crushed.
Alternate Name/s: Horse chestnut, fetid buckeye, stinking buckeye
Native Range: Texas and Oklahoma as well as places in the Midwest, Southeast, Mid-Atlantic and New England
Habitat: Moist stream banks, bottomlands, woodlands, thickets
Type: Deciduous tree
Height: 20-40′ (to 75′ in the wild)
Bloom Time: Mid to late spring
Bloom Color: Greenish yellow
Light: Full sun to partial shade
Soil: Average, medium moist, well-drained, slightly acidic
USDA Hardiness Zones: 3-7
Photo Credit: Wikipedia
Red Buckeye (Aeculus pavia)
Red buckeye is a clump-forming deciduous shrub or small tree with an irregular rounded crown. Its palmately compound leaves usually have 5 elliptical leaflets that are 4-8″ long, have toothed margins, and turn an unremarkable red in the fall. In spring, 4-10″ long panicles of red to orange-red flowers (occasionally yellow) appear. The flowers are narrowly tubular, 1-1.5″ long, and may have exerted stamens. The fruit that follows is a 1-3″ long tan leathery capsule with 1-3 seeds. The flowers are attractive to hummingbirds, butterflies and other pollinators and the seeds are eaten by squirrels.
Alternate Name/s: Firecracker plant, scarlet buckeye, red horse chestnut
Native Range: Oklahoma and Texas as well as places in the Midwest, Southeast, Mid-Atlantic and New England
Habitat: Wooded slopes and valleys, along streams, in thickets.
Type: Deciduous small tree or shrub
Height: 12-25′
Bloom Time: Spring
Bloom Color: Red to orange-red, occasionally yellow
Light: Partial shade to full sun
Soil: Average, medium moist, well-drained
USDA Hardiness Zones: 4-8
Photo Credit: Wikipedia
For the purpose of this article, the Southwest includes the states of Texas, Oklahoma, New Mexico and Arizona. Other states often associated with the Southwest are included in other geographic areas. The key factor linking these four states is aridity. The area includes high dry plains and true deserts as well as spurs of the Rocky Mountains. Only Texas has a coast on the ocean which brings more precipitation and humidity to east Texas and Oklahoma than elsewhere in the area. In addition to the ocean, the Rio Grande and Colorado Rivers are significant water features in the area. Although temperatures in the mountains can be cool, most of the area experiences hot temperatures for a long period each year.