"Pouch" on a Lady Slipper?

Q) What is the purpose of the ‘pouch’ on a lady slipper? Allison R.

A) Botanists classify flowers as orchids by their structure. Typical blooms have 3 petals and 3 sepals that alternate around a central column. The lower petal is called the ‘lip’ or throat and is usually a different color. The purpose of the throat is to attract pollinators as both the male and female parts are found within. Additionally, the throat often emits a fragrance to lure potential suitors. Common flowers such as roses, daffodils, and petunias have entirely different configurations.

Yet the lady slipper on first glance looks nothing like the stereotypical orchid in its shape. It seems to be missing two lower sepals and instead of a throat, there is a pouch! Closer examination reveals that the pollen sacks are found in two different locations. Certainly, this flower must belong in another plant family.

In the cloud forests where many orchids are native to, there reside carnivorous ‘pitcher’ plants which boast pouch-like growths. Deep within each pouch lies a sticky substance and slippery sides that help to ensure that those which enter the cavernous opening do not leave. The pouch then takes on the function of a stomach and literally digests the insect with the help of some enzymes. There is a top lid that hangs over the pouch to deflect rainfall.

In other wooded areas, another type of carnivorous plant called a Venus Fly trap gobbles up insects who dare to land on the colorful and scented pads. It only takes one tenth of a second for their ornate jaws to close and as the insect wiggles to escape, the trap tightens completely and begins digestion. It’s a dangerous world out there!

Over the years, there have been attempts to move lady slippers out of the orchid family. For now, however, botanists cite that the two lower sepals are ‘fused’ together, shrunken, and are positioned directly behind the pouch. The ‘pouch’ is used for pollination where an inquisitive fly cannot resist entering. The insect does not get gobbled up and digested but instead helps to propagate the orchid by inadvertently capturing the pollen on its back as it travels to the next flower. As with the pitcher plant, water is kept out of the pouch by a top lid or dorsal sepal (in technical terms) that hangs over slightly. Mother Nature at its finest!

The entire lady slipper family, which includes Paphiopedilums and Phragmepediums, is a favorite among hobbyists due to their low light requirements and long lasting blooms. Often considered excellent companion plants for the omnipresent Phalaenopsis, these lovely orchids provide much enjoyment for growers of all skill levels. 

Thursday, March 1, 2012 - 17:00