Mutant Peace Lily

These plants normally produce one white flower, but this one bears three. Look closer, and it will be seen that the larger has two petals. Look closer still, and the smaller flower actually has three petals (two upright and one curled underneath). The plant also has a split leaf -- not a natural tear, but a leaf which divides halfway along to form two points -- and a couple of fused stems. What mysterious source of radiation lurks beneath our living room windowsill to have caused this?