Cypripedium - Characteristics

Characteristics

As with most terrestrial orchids, the rhizome is short and robust, growing in the uppermost soil layer. The rhizome grows annually with a growth bud at one end and dies off at the other end. The stem grows from the bud at the tip of the rhizome. Most slipper orchids have an elongate erect stem, with leaves growing along its length. But the Mocassin Flower (Cypripedium acaule) has a short underground stem with leaves springing from the soil. The often hairy leaves can vary from ovate to elliptic or lanceolate, folded along their length. The stems lack pseudobulbs.

The inflorescence is racemose. It can carry one to twelve flowers, as in Cypripedium californicum. But most species have one to three flowers. There are three sepals, with, in most species, the two lateral ones more or less fused. The flower has three acute petals with the third a striking slipper-shaped lip, which is lowermost. The sepals and the petals are usually similarly colored, with the lip in a different color. But variations on this theme occur. The aspect of the lip of different species can vary a great deal. As with all orchids, it is specially constructed to attract pollinators. The flowers show a column with a unique shieldlike staminode. The ovary is 3-locular (with three chambers).

Read more about this topic:  Cypripedium