Mid-century vintage USA pottery vase, ivory white berry and leaf pattern

Unmarked vintage USA art pottery vase, 7 1/2" tall. The ivory white glaze is glossy, or semi-gloss, not as matte finish as it looks in the photos.

This leaves and berries design we thought looked like Nelson McCoy, though the unglazed bottom of this piece didn't look like any McCoy pottery we'd ever seen. And we haven't been able to positively identify this pattern at all, sorry!

We do know that it's at least 50 years old, and USA made. It's in very good condition, no chips or cracks. It's a little dusty and dirty inside, though the glazed exterior looks great, without rubbing or scratching.