Hydrangea L.

Chile Central

"Notes: Western Ghats, Cultivated, Native of East Asiatic Region"

Wild Hydrangea is occasional to locally common in southern Illinois, uncommon in central Illinois, and largely absent from the northern section of the state. Habitats include shaded ravines, rocky stream banks in wooded areas, bottoms of bluffs and cliffs, low rocky ledges, and similar habitats in wooded areas. Wild Hydrangea is found in high quality natural areas. It is also cultivated in gardens.

This native shrub is 3-8' tall, producing unbranched canes that are erect. Young tips of the central cane are light green and sometimes pubescent, otherwise the cane is woody with gray to brown bark. With age, this bark tears off into multicolored sheets, providing it with a tattered appearance. Pairs of opposite leaves occur at intervals along each cane. These leaves are about 4-6" long and 3-5" across; they are oval-ovate or oval-cordate and serrated along their margins. The upper surface of each leaf is medium to dark green and hairless, while the lower surface is pale green and either hairless or sparsely pubescent. The slender petioles are 2-6" long and either hairless or pubescent. Each cane terminates in a flat-headed panicle (or compound cyme) of flowers about 3-6" across. In the center of the panicle, there are numerous fertile flowers that are very small in size, while around the outer margin of the panicle there are a few sterile flowers that are larger in size (about ¾" across). However, sterile flowers are occasionally absent in some populations of wild plants. Each fertile flower has a short light green calyx with insignificant teeth, 5 tiny white petals less than 1/8" long, 8 or 10 stamens with long filaments, and a pistil with a pair of styles. The fertile flowers are either greenish white or cream-colored. Each sterile flower has 3-4 petaloid bracts that are large and white. The branches of the panicle are dull cream-colored and usually pubescent. The blooming period occurs from early to mid-summer. The fertile flowers are in bloom for only a short time, while the sterile flowers remain attractive until the fall. Each fertile flower is replaced by a small 2-celled seed capsule about 1/8" across that has a pair of tiny curved horns on its upper surface. The sides of the capsule are ribbed. Each capsule contains many tiny seeds that are flattened; they are small enough to be blown about by the wind or carried by currents of water. The root system can develop vegetative offsets from underground runners. As a result, colonies of plants are often formed.