T he structure of orchid flowers is unique among floral plants. The orchid flower is typically has an outer whorl of three sepals, an inner whorl of three petals, and a single large column (the gynostemium, composed of the male stamens attached to the female pistil) in the center.The sepals are the protective cover of the flower bud.his is the primary identification feature of an orchid. At the top of the column is the male anther which contains packets of pollen called pollinia. Below the anther is the stigma, a shallow, usually sticky cavity in which the pollen is placed for fertilization.