Round-headed leek flower head (3rd of 5 images). Close-up of the developing flower head of the round-headed leek, Allium sphaerocephalon. The flower head consists of many tiny flowers called florets. The remains of the papery bract which protected the florets when they were in the bud can be seen at centre left and right. A. sphaerocephalon is a medium sized perennial plant which grows in grassy places, rocks and dunes, and flowers between June and August. See photos B640/116-120 for the sequence of flower opening.