Mod ball shapes in stair stepped sizes, retro vintage pottery planter in natural earth tones

Mid-century vintage ceramic ivy planter or flowerpot, a chain of balls in graduated sizes, 10" long end to end. This isn't marked with a maker that we could find, though it looks like late 50s - early 60s California studio pottery to us? It's in nice shape, no chips or cracks, a little dusty with soil remains.