Rhus virens aka Evergreen Sumac. Everything I can find shows small red fruit up to 1/4" in diameter. All the photos my search turned up showed red fruit, but they were all still on the plant. To me, that would leave open the question of whether they retained the red color when they were completely cured (dry) or not. What shouldn't change is the presentation of how those seeds are displayed. All the photos showed a sort of loose spray of seeds that had followed the blooms. If what you are seeing shows that configuration, then you are probably seeing either thoroughly dried seeds or seeds that blasted and dried up instead of maturing. I would suspect immature dried seeds which wouldn't be viable. I would think the blooms from earlier this year still might retain some color and any from an early fall bloom set to be fairly bright if they were viable. It could be the plant needs a pollinator that wasn't handy if it bloomed, or has male or female plants and yours is a male, or it may be it has to reach a certain stage of maturity before it will set seeds. Since it is apparently popular with some birds etc., the seeds it produced this year may have been stripped off before you were looking for them.
I'm trying to grow a small clump of three Diospyros texana aka Black Persimmon or Texas Persimmon or Chapote. They bloomed, but not well and didn't set any fruit. They are either male or female so it's possible all three are males and will never set fruit. They are still in the establishment phase of life here and also on a marginal northern range for cold tolerance so it remains to be seen how successful they will be as plants here.
Good luck!
