Flower of Brassica rapa with one sepal, 2 petals, and 2 stamens removed. The complete flower has 4 distinct sepals, 4 distinct petals, 6 stamens (tetradynamous with 4 long and 2 short), and a syncarpous gynoecium of 2 carpels and a superior ovary. This example is canola (Brassica rapa) .
Photo by K. R. Robertson taken in Mason County, Illinois.