Fig. 1. The phenotypes of Arabidopsis wild-type and mutant mature flowers. All photographs are at the same magnification. One sepal was removed to show the interior organs except for flowers in A, B, E, F and T. (A) A wild-type flower showing sepals (s), petals (p), stamens (st), and carpels (c). (B) An ask1-1 flower with 3 sepals; two of them are small and one is fused with stamen tissues (chimeric petal, cp). The stamens are shorter than normal. (C) A ufo-2 flower with abnormal organs interior to whorl one, including sepals (s), sepal-like organs (sl), one petal-like organ (pl) and one normal stamen. (D.) A ufo-2 ask1-1 flower showing sepal, sepal-like, filament (f) and stamen-like (stl) organs. (E) A ufo-6 (weak allele) flower with normal petals, stamens, and one petal fused with stamen tissues. (F) A ufo-6 flower with a normal petal, two chimeric petals and normal stamens. (G) A ufo-6 ask1-1 flower showing a stamen-like organ with carpel tissues (arrow). (H) A ufo-6 ask1-1 flower with sepals and filaments interior to whorl one. (I) An ap3-1 flower with four sepals in whorl two and stamens in whorl three. (J) An ap3-1 ask1-1 flower showing sepals and filament fused with carpel tissues (arrow) interior to whorl one. (K) An ap3-1 ask1-1 flower with sepals and carpel-like organs (arrow) interior to whorl one. (L) An ap3-3 flower with sepals, filaments and carpel-like organs interior to whorl one. (M) An ap3-3 ask1-1 flower with a similar phenotype to the ap3-3 but with fewer sepals. (N) An ap3-3 ask1-1 flower showing two small sepal-like organs (arrows). (O) An ap3-3 ufo-2 ask1-1 triple mutant flower with only one sepal between whorls one and four. (P) An ap3-3 ufo-2 ask1-1 flower showing no organs between whorls one and four. (Q) A pi-1 single mutant flower. (R) A pi-1 ask1-1 flower with fewer sepals than the pi-1. (S) A pi-1 ufo-2 ask1-1 triple mutant flower showing only one filament-like organ (arrow) and carpels fused with ovule-like tissues (arrowhead). (T) A sup-1 single mutant flower showing 11 stamens. (U,V) Two sup-1 ask1-1 double mutant flowers showing a reduced number of stamens and an increase in carpel structure. The flower in U has fewer, smaller stamens and more carpel-like organs than the sup-1 (Arrow indicates a small petal, which is often found in the ask1-1 mutant flower). The flower in V has normal carpels in the center and seven stamens with short filaments, as in the ask1-1 flower. (W) sup-1 ufo-2 flower with a reduced number of stamens (arrow points to a normal stamen with pollen grains) and a carpel structure larger than that in sup-1. (X) A sup-1 ufo-2 ask1-1 triple mutant flower showing a large gynoecium in the center and a near absence of organs between the outer sepals and the central gynoecium.