By V. M. WATTS
Nature Magazine, March 1932
Of the orchids, dainty tribe of practical jokers, one of the cleverest is the magenta-flowered grass pink, Calopogon pulchellus. She invites a flying guest to dine and places before him artificial viands. She gives him scarcely time enough to discover the hoax before she springs a trap and tumbles him, head over heels, out the front door. As he goes she adds the practical touch to her joke, loading him with parcels to be delivered to the next temptress who may manage to lure him to her false banquet.
The equipment and technique of this pretty trickster are quite worthy of examination. In the first place the color of the flower seems to attract insects, especially certain species of small bees. On the bloom's lip, which in this case is upright, is the little tuft of golden hairs responsible for the name, Calopogon, which is derived from Greek words meaning "beautiful beard." Since the beard very much resembles a group of stamens it constitutes a special invitation to pollen-gathering insects.
THE GRASS PINK
Now it so happens that the lip is delicately hinged at the base, and when the weight of even a very small insect is placed upon it a sudden forward and downward swing results, depositing the insect in an inverted position upon the column of the flower. The back of his abdomen receives an application of sticky stigmatic fluid. Then as he slides past the end of the column his weight ruptures the tiny pouches which contain the pollinia, or pollen masses of the flower. These little particles become attached by means of fine, gossamer-like threads to the sticky spot on his back, and our industrious little friend is burdened with a load for which he has no use and which he cannot discard until he again allows himself to be lured by false promises. One would think that if the bee had the intelligence for which he is reputed he would soon learn to avoid this species, but the same insect may visit many plants of the group within a short time. On the stigma of each blossom he deposits the pollinia that he received from its predecessor.
It is to this amusing but highly efficient method of pollen transfer that this unique plant owes its abundance in many parts of eastern United States, for like most orchids it is self-sterile. Unlike many insect-pollinated plants it repays the bee for his services in neither nectar nor edible pollen – nothing, in fact, but a tumble, unless, indeed, the guest considers himself rewarded by the beauty of his reception room, a beauty much appreciated by flower lovers.