There are two sepals which fall off before the petals expand.
The four sepals are arranged symmetrically, an outer median and an inner lateral pair.
From the upper rim of the receptacle are given off the five sepals, the five petals, and the very numerous stamens.
There are five free sepals, overlapping in the bud, and, alternating with these, five free petals.
Thus, in a phanerogam, the sepals, petals, stamens and foliage-leaves all come under the category leaf, though some are parts of the perianth, others are spore-bearing organs (sporophylls), and others carry on nutritive processes.