The orchids which are seen in such variety of form and color in our greenhouses are mostly importations from tropical countries. The Family is represented with us by several of our dearest wild flowers. Their structure is complicated, but can be understood by studying some of the larger members of the Family. It is especially designed to secure insect pollination. The perianth is composed, usually, of six divisions, the three outer sepals often colored, not green. Of the three inner, the petals, one is larger than the others, and is called the lip. This is variable in shape, perhaps prolonged into a deep spur at its base, perhaps being a sac or pocket (as in the moccasin flower), perhaps fringed, always a conspicuous part of the flower. This is the platform - the front door, so to speak - for the insect to stand upon while pushing its head into the interior as it seeks the coveted nectar. Cypripediums have two good stamens, with the rudiment of a third. All other genera have but one fertile stamen, which is called the column, joined in a peculiar manner to the style. These organs are, to the uninitiated, quite unlike those of all other flowers. The pollen grains in the single anther are collected into masses called pollinia, and, if an insect enters such a flower and rubs its head against the ripe anther, the entire contents of the anther are pulled out, the insect flying away with the pollinia adhering to its proboscis in what would seem to be an uncomfortable manner. Entering another flower, the little creature is relieved of its superfluous burden, leaving the pollinia upon the rough or sticky stigma.
There are 7,000 species of orchids known, and for grace, beauty of form and color, they stand unrivalled in the flower kingdom.