Hydrangea serrata is the commonly-used abbreviation of the species for which the correct botanical nomenclature is Hydrangea macrophylla ssp. serrata. It is worth remembering that H. serrata is a subspecies of H. macrophylla as they share many common attributes: (1) both can flower as mopheads or lacecaps, but the majority of H. serratas are lacecaps; all other hydrangea species flowers are regular or irregular panicles, (2) both can flower as ‘pinks’ or ‘blues’ dependent of soil chemistry; all other hydrangea species flower white but may age to green or pink, (3) they share the same cultivation needs, (4) pruning techniques are the same for both, (5) propagation techniques are the same for both. Generally speaking, the major difference between H. serrata and H. macrophylla is that H. serrata cultivars tend to be smaller, usually topping out at 1.2m – but, as always in horticulture, there are exceptions. Despite the above, many hydrangea experts prefer to view H. serrata as a separate species.
Just to add another level of complexity, some cultivars, e.g., ‘Preziosa’ are suspected of being a hybrid between H. macrophylla and H. macrophylla ssp. serrata and should therefore be named H. macrophylla x serrata ‘Preziosa’.
Native to woodland mountain valleys of Japan, from the islands of Hokkaido in the north to Kyushu in the south and on the South Korean island of Ulleung-do.