You are probably talking about P. coronarius but P. lewisii is prevalent in commerce at this time due to interest in native plantings. You might as well plant the native, unless there is something about P. coronarius you are trying to capture. If you want to see who had what (among the many participating nurseries) some years back see The Plant Locator - Western Region (2004, Black-Eyed Susans/Timber, Portland). I like P. lewisii 'Blizzard' because it has dark purple stems that contrast with its profuse flowers, making it more than just a green bush with white flowers.

My mother remembers a "Snowball Bush" that was in her grandmothers yard and would like to have one, but I haven't been able to figure out what it was because it's a common name for different things, likely either some type of hydrangea or viburnum. The thread below lists some things that it might be and said the bloom time can be a clue. Maybe you could just google some images of each one. I think a hydrangea would be in bloom longer than a viburnum. Here is a link that might be useful: Snowball Bush

Does Winesap ring any bells? Here is a link that might be useful: My Blog

Good for thinking outside the box. Think twice about rose of sharon. Leafs out very late and is an ugly bundle of sticks till then. Unless it is one of "sterile' new cultivars they seed like crazy and you will be plucking seedlings all the next summer. But some, I don't remember if its the Satin or chiffon series are sterile. But again, they don't do or look like anything except for the three or four weeks they bloom. Lilacs....nothing....three weeks of bloom then nothiing. Do a mixed selection. Maybe you'll accept the 'suggestion' or reference to old fashioned without actually planting old style plants that have just one season of interest. (not that some new styles don't do any thing for 3/4 of the growning season) I live in a house built in 1811. I don't have a volunteer crew like an "showcase" historic house. owned by a historical society. Old fashioned isn't necessarily more beautiful, more fragrant, less bug susceptible.