You might find this species & cultivars list helpful. https://en.wikipedia.org/wiki/Deutzia

More D. scabra’s images. Click on images to enlarge. https://www.discoverlife.org/20/q?search=Deutzia

This link has a very good description for the leaves of D. scabra. https://www.uaex.edu/yard-garden/resource-library/plant-week/deutzia-fuzzy-6-21-13.aspx

More images & information for D. crenata species. https://plants.ces.ncsu.edu/plants/all/deutzia-crenata/

You’re welcome daviddt4! Sorry, I’m not an expert of this genus & and there are numerous cultivars to add to the confusion. Perhaps these links can help you further. On the first link double clicks on the image to look the Deutzia crenata leaves margin to compare to those in the D. scabra. Best wishes daviddt4. Laura https://en.wikipedia.org/wiki/Deutzia_crenata

Thank you, Laura. You pegged it! It is cultivar ‘plena’, double flower, but I can not distinguish between Deutzia scabra & Deutzia crenata. They are very similar. I have no other shades of color in the blooms, only bright white. Do you know how to distinguish between these 2 species? I will search as well. Thanks!

A cultivar of D. scarbra https://commons.wikimedia.org/wiki/File:Deutzia_scabra_D.jpg

Link for Deutzia scabra. https://en.wikipedia.org/wiki/Deutzia_scabra

Maybe something in the Deutzia genus? Sorry, I can’t tell which species or cultivars yours is. Check out cultivars of D. scabra & D. crenata Click on images from these included link below to enlarge. Best wishes! Link for Deutzia crenata species. https://en.wikipedia.org/wiki/Deutzia_crenata