( Originally Published 1922 )
Spreading Dogbane; Fly-trap Dogbane; Honey-bloom;
Flowers—Delicate pink, veined with a deeper shade, fragrant, bell-shaped, about 3 in. across, borne in loose terminal cymes. Calyx 5-parted; corolla of 5 spreading, recurved lobes united into a tube; within the tube 5 tiny, triangular appendages alternate with stamens; the arrow-shaped anthers united around the stigma and slightly adhering to it. Stem: 1 to! 4 ft. high, with forking, spreading, leafy branches. Leaves: Opposite, entire-edged, broadly oval, narrow 1 at base, paler, and more or less hairy below. Fruit: Two pods about 4 in. long.
Preferred Habitat—Fields, thickets, I beside roads, lanes, and walls.
Distribution—Northern part of British Possessions south to Georgia, westward to Nebraska.'
Everywhere at the North welcome across this interesting, rather shrubby plant, with its pretty but inconspicuous little rose-veined bells suggesting pink lilies-of-the-valley. Now that we have learned to read the faces of flowers, as it were, we instantly suspect by the color, fragrance, pathfinders, and structure that these are artful wilers, intent on gaining ends of their own through their insect admirers. What are they up to?
Let us watch. Bees, flies, moths, and butterflies, especially the latter, hover near. Alighting, the butterfly visitor unrolls his long tongue and inserts it where the five pink veins tell him to, for five nectar-bearing glands stand in a ring around the base of the pistil. Now, as he with-draws his slender tongue through one of the V-shaped cavities that make a circle of traps, he may count himself lucky to escape with no heavier toll imposed than pollen cemented to it. This granular dust he is required to rub off against the stigma of the next flower entered. Some bees, too, have been taken with the dogbane's pollen cemented to their tongues. But suppose a fly call upon this innocent-looking blossom? His short tongue, as well as the butterfly's, is guided into one of the V-shaped cavities after he has sipped; but, getting wedged between the trap's horny teeth, the poor little victim is held a prisoner there until he slowly dies of starvation in sight of plenty. This is the penalty he must pay for trespassing on the butterfly's preserves! The dogbane, which is perfectly adapted to the butterfly, and dependent upon it for help in producing fertile seed, ruthlessly destroys all poachers that are not big or strong enough to jerk away from its vise-like grasp. One often sees small flies and even moths dead and dangling by the tongue from the wicked little charmers. If the flower assimilated their dead bodies as the pitcher plant, for example, does those of its victims, the fly's fate would seem less cruel. To be killed by slow torture and dangled like a scarecrow simply for pilfering a drop of nectar is surely an execution of justice medieval in its severity.