VINTAGE RUTH NORMAN SAKS FIFTH AVENUE CAFTAN MAXI DRESS RED WHITE BLUE PURPLE. Mandarin collar. It says petite on tag. I am size xl and tried it on. It does go on but it is not flowy as it should be. I think M/L,  perhaps S if you like things a bit oversized. Front zipper. I think that they also considered this a hostess gown. Pattern is beautiful!