Rose family (Rosaceae)
Description: This small native shrub is 3-6' tall; it branches readily and becomes bushy in appearance. The woody stems are brown to grey and become more rough or winkled with age. The alternate leaves are up to 4" long and 2½" across; they are oval-ovate or obovate in shape, finely serrate or finely crenate along the margins, and hairless. The leaves are often broadest beyond the midpoint and they have short obtuse tips. The lower surface of each leaf is a lighter shade of green than the upper surface. The upper midvein of each leaf has tiny black glands that are best observed with a hand lens. At the base of each leaf, there is a slender petiole. The flowers develop from the upper and outer branches in compound cymes; each compound cyme has about 12 flowers, although their abundance varies. Each flower is about ½" across, consisting of 5 white rounded petals, a reddish green calyx with 5 short teeth, and about 16 stamens surrounding the styles in the center. The conspicuous anthers of the stamens are pink. While each flower is rather small, they are produced in abundance. The blooming period occurs during the late spring and lasts about 3 weeks. During late summer, each fertilized flower is replaced by a black leathery fruit containing several small seeds. This fruit is globoid and about 1/3" across. The mature fruits of Black Chokeberry are deciduous and fall to the ground within a short period of time. The deciduous leaves become bright yellow, orange, or red during the fall. The root system consists of a woody branching taproot. This species occasionally forms large colonies, but this is uncommon.
Cultivation: The preference is light shade to full sun, moist to dry conditions, and a sandy acid soil. Some populations of this shrub occur in areas with considerable moisture, while other populations can be found at surprisingly dry sites. This can affect the adaptability of individual plants.
Range & Habitat: Black Chokeberry is occasional in sandy areas of NE Illinois, otherwise it is rare or absent (see Distribution Map). Habitats include sand prairies, sandy shrub prairies, hill prairies, thickets, sandy savannas, sandy areas along woodland paths, sandstone glades, rocky bluffs, and bogs. In southern Illinois, where it is rare, this shrub is restricted to glades and rocky upland woods. In wooded areas, occasional wildfires are probably beneficial in maintaining the habitat of this species as this reduces competition from taller canopy trees (e.g., Black Oaks). Black Chokeberry is one of the shrubs that invades mesic sand prairies, sometimes forming its own 'shrub prairie.'
Faunal Associations: The nectar and pollen of the flowers undoubtedly attract bees and other insects. Among the bees, Osmia spp. (Mason Bees) and Andrena spp. (Andrenid Bees) are common visitors of spring-blooming shrubs in the Rose family. The caterpillars of the butterfly Satyrium titus (Coral Hairstreak), the moth Catocala praeclara (Praeclara Underwing), and the moth Lomographa semiclarata (Bluish Spring Moth) feed on the foliage of Aronia spp. (Chokeberries). Some birds use Chokeberries as a food source, including the Ruffed Grouse (buds, fruit) and Cedar Waxwing (fruit). Because the mature fruit of Black Chokeberry is black and soon falls to the ground, it is especially likely to be eaten by various mammals, including the Black Bear, Red Fox, and Fox Squirrel. These birds and mammals help to disperse the small seeds in the fruit. Both the Cottontail Rabbit and White-Tailed Deer browse on the twigs and foliage to a limited extent.
Photographic Location: The photographed shrubs were growing along nature trails in a sandy savanna and a sandy thicket in Kankakee County, Illinois.
Comments: Black Chokeberry is one of the spring-flowering shrubs of the Rose family that most people are unfamiliar with. It remains quite small in size and lacks thorns. Another native species, Aronia arbutifolia (Red Chokeberry), has pubescent leaves and red fruits. Sometimes these two species hybridize to produce Aronia X prunifolia (Purple Chokeberry), which has purple fruit and other characteristics that are intermediate between its two parents. Chokeberries are somewhat similar to Malus spp. (Crabapples), except that the latter produce larger flowers (1-2" across) in simple cymes. Both Chokeberries and Crabapples produce fruits containing several small seeds. Other shrubs and small trees of the Rose family produce fruits containing a single stone (a large seed with a hard covering). This includes the various Prunus spp. (Cherries, Plums).