This is a very unusual shaped planting dish. My guess is that it probably has candlesticks out there somewhere.
It has an almost kidney shape to it with a little atomic angles thrown in. One side is plain and the other side has shaped wave like folds. The color is that soft blue that was so popular in the 1940/50s.
It measures 17 inches long x 6 inches wide x 3.5 inches deep.
The bottom is incised marked: Maddux of California / U 50 C.
It is in excellent condition. There are no chips or cracks