Philadelphus mexicanus Schltdl.

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.

Mexico, Guatemala.

Source: Spencer, R. (2002). Hydrangeaceae. In: Spencer, R.. 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.

kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Asteranae
order      Cornales
family       Hydrangeaceae
genus        Philadelphus L.