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.
BUCKWHEAT FAMILY
(Polygonaceæ)
This family is divided into seven genera and many of these are further divided. They are all inconspicuous in flower. The genus Rumex, to which our common Sorrels belong, contain seventeen species: that of Polygonum, which contains the Knot-weeds, has 32 species included in its six sub-genera.
(A) Lady’s Thumb; Persicaria; Knotgrass (Polygonum persicaria) (European). This is a very common weed everywhere in damp places, especially about farmhouses. The small, crimson-pink flowers are in dense spikes terminating the branching stems that are from 1 to 3 feet high. The lanceolate pointed leaves, that alternate along the angled and sheathed stem, are rather rough and usually have a dark triangular spot in the middle.
(B) Common Smartweed; Water Pepper (P. hydropiper) has similar shaped flowers of a greenish color. The leaves are lanceolate and very acrid. It is very abundant in wet places throughout our range.
