The red-berried elder complex is variously treated as a single species Sambucus racemosa found throughout the colder parts of the Northern Hemisphere with several regional varieties or subspecies. I believe this photo is a Sambucus pubens. It is blooming in the woods at Distant Hill Gardens in Walpole, New Hampshire.
This is a somewhat common plant is this part of New England. Small red berries, that are not edible, will ripen in July. We have another native plant, Common Elder or Elderberry - Sambucus canadensis, that flowers later in the summer. The Common Elderberry has small edible black berries that make excellent jelly and 'Elderberry' wine.
Jason Sharp;
Hillsborough County, Florida
The Adoxaceae is a small family of flowering plants in the order Dipsacales, as now constituted comprising four genera and about 150-200 species. It is characterised by opposite toothed leaves, small five- or, more rarely, four-petalled flowers in cymose inflorescences, and the fruit being a drupe. They are thus similar to many Cornaceae.