Fig. 4. SEMs of seu-1 ag-1 and seu-1 lug-1 ag-1 flowers. Number indicates whorl number. (A) An ag-1 flower. Whorl 1 organs are sepals, and whorls 2 and 3 organs are petals. Whorl 4 is another flower repeating the (sepal-petal-petal)_n pattern. (B) A seu-1 ag-1 double mutant flower. Whorl 1 organs are narrow sepals. Whorls 2 and 3 are narrow petals. Whorl 4 is another flower. (C) A seu-1 lug-1 ag-1 triple mutant flower. The whorl 1 sepals are very narrow and canoe-shaped. Whorls 2 and 3 organs are either blade-like or club-like (arrowhead). (D) A close-up image of the epidermal cells in the blade-like organ. These epidermal cells exhibit characteristics of petal cells. (E) A close-up image showing several developing blade-like organs (arrowhead) in whorls 2 and 3 of a seu-1 lug-1 ag-1 triple mutant flower. (F) A close-up image showing several club-like organs (arrowhead) in whorls 2 and 3 of a seu-1 lug-1 ag-1 triple mutant flower. Scale bars in A, B, and C are 1 mm; scale bar in D is 10 µm; scale bars in E and F are 100 µm.