The four sepals are arranged symmetrically, an outer median and an inner lateral pair.
There are five free sepals, overlapping in the bud, and, alternating with these, five free petals.
There are two sepals which fall off before the petals expand.
From the upper rim of the receptacle are given off the five sepals, the five petals, and the very numerous stamens.
The sepals and petals are free or more or less united, the stamens as many or twice as many as the petals; the carpels, usually free, are equal to the petals in number, and form in the fruit follicles with two or more seeds.