Blossoms

The orchids are a relatively young plant family which has probably evolved from the lilies. Lilies have six more or less equal petals and the blossoms can be rotated or mirrored over one of the three different symmetry axes without losing their functionality. The center of a lily blossom usually bears a stigma and six stamens with free pollen.

Orchids, however, have developed more asymmetric blossoms which can be mirrored only over one symmetry axis. One of the inner petals has become very big and colorful. This "lip" protrudes from the blossom and is used as a landing place for insects. In the young bud, the lip is usually pointing upwards. The ripe seed-vessel of the most species turns around 180 degrees, so that the lip is pointing downwards. Orchid blossoms have only one or two stamens which are bundled together with the stigma in a small column, the Gymnostenium.