I'll try to attach a photo of ash. Also, if you look at the area of that board that is vertical grain there is not a single medullary ray seen. I may be wrong but with white oak I would expect to see at least one. One photo of my ash floor and a closeup:
At first glance I side with with white oak, but looking a little longer, it looks like ash. So there you have it, by general consensus based upon your photo, ash edges out oak by a slim margin--and I'm not much help on this at all. To have in hand would allow a better identification.
The open pores are too long for red oak, so I’d rule that out. I definitely lean toward white oak over ash, but I’ve handled a lot more white oak than I have ash, so it could just be that bias. Is there any ray fleck on the edges? As others have said, the easiest way to determine between white oak or ash would be a smell test.
I inspected about 25,000 board feet of Ash this week...saw a thousand boards that looked just like that. Last week I inspected about 85,000 board feet of White Oak...didn't see any boards that matched. Similar, maybe but not the same. It's Ash.