Characteristics
The inflorescence of smooth hydrangea is a corymb. The showy, sterile flowers are usually absent or if present they are usually less than 1 cm in diameter. Flowering occurs May to July. Fruit is a ribbed brown capsule about 2 mm long; many are produced.
The leaves of smooth hydrangea are large (8 to 18 cm long), opposite, serrated, ovate, and deciduous. The lower leaf surface is glabrous or with inconspicuous fine hairs, appearing green; trichomes of the lower surface are restricted to the midrib and major veins.
The stem bark has a peculiar tendency to peel off in several successive thin layers with different colors, hence the common name "sevenbark".
Smooth hydrangea can spread rapidly by stolons to form colonies.
Read more about this topic: Hydrangea Arborescens