Climbing evergreen shrub with prominent exposed buds. Leaves ovate-lanceolate to 8-9 cm long or more, slightly bristly on both surfaces, entire or with a few small teeth. Flowers 1 or 3 together, each to 4.5 cm wide, creamy white, fragrant; summer. Sepals hairy.
P. hirsutus Nutt. from SE USA is a low shrub with branches slightly arching and twisted and leaves with both surfaces shaggy-hairy.
Source: (2002). Hydrangeaceae. In: . Horticultural Flora of South-eastern Australia. Volume 3. Flowering plants. Dicotyledons. Part 2. The identification of garden and cultivated plants. University of New South Wales Press.