Along with modifications involving the above structures two other conditions play a very important role in the sexual reproduction of flowering plants, the first is timing of flowering and the other is the size or number of flowers produced.
沿著與涉及上述結構的修改的其他兩個條件起到開花植物的有性繁殖非常重要的作用，首先是開花的定時，另一個是大小或產生花數。