Birthwort Family (Aristolochiaceæ)
A small family of low herbs or twining vines, with but two genera and few species.
Wild Ginger (Asarum canadense) may be found flowering in rich woods during April and May, from Me. to Mich. and southward. It has two large, heart-shaped leaves on long petioles from the base; deep green above and lighter below, soft, wooly, and handsomely veined.
The leaves are very beautiful, but it is the solitary flower that makes this plant so interesting. Small, dully colored, on a weak, short stem that barely raises it above ground and often leaves it concealed by the dead leaves that carpet the woods in early spring.
The flower is bell-shaped, with three short, sharply-pointed spreading lobes; six stamens with short anthers and a thick style with six radiating stigmas. Another species (grandiflorum), found in Va. and N. C., has but one leaf and flowers twice as large, or two inches in length.
Pipe Vine; Dutchman’s Pipe (Aristolochia macrophylla). The Dutchman’s Pipe is chiefly a southern plant or vine, being found from Pa. and Minn. southward. It has a woody, climbing stem that may attain lengths of from 10 to 40 feet. The very large, deep-green, veiny leaves that alternate along the stem are very beautiful. In the dull, greenish-yellow flowers, however, lies the chief interest of the botanist. Its stigma matures and withers away before the ripening of the pollen, thus making the plant dependent upon insects for its perpetuation.
The throat is filled with tiny hairs, all pointing inward, so ingress is easy but egress impossible. Entering insects are held prisoners, living upon the nectar, until the stigma withers and pollen ripens; after this the hairs in the throat lose their rigidity and the pollen-dusted and well-fed prisoners are allowed to escape. Their memories are poor or the pollen feast is well worth the imprisonment, for they usually immediately hie to another blossom and force their way in, of course pollenizing the flower in so doing.