Apocynum cannabinum L.
June to August N Family: Apocynaceae
Flower: Clusters of bell-shaped white to greenish white flowers tip the stems. Each flower bell has five triangular lobes on the rim. The pistil is a mound in the center of the flower.
Leaf: The opposite leaves have no or very short petioles. The leaf blade is bright green. The midvein and main side veins are almost white.
Stem: The main stem is stout and has many opposite paired branches. The main stem reaches four feet. The stems are reddish.
Fruit: The fruit is a long pod five or six inches in length. The seeds are lined up inside the pod. They are topped by a tuft of hairs.
Habitat: This plant is common along roads. It grows in a wide variety of places but likes to be in the sun.
Poisonous: All parts are poisonous.
Much of the summer Prairie Dogbane lines the roads. At times the stands of plants are thick enough to overwhelm all but seeding grasses. The plants send out rhizomes creating colonies that can become a problem in pastures.
Superficially dogbane resembles various milkweeds with its opposite leaves. Even Monarch butterflies get confused occasionally and lay eggs on dogbane but the luckless caterpillars do not survive. The easy distinguishing characteristic is the branches. Dogbane branches. Milkweeds do not.
Breaking a stem or tearing a leaf releases a white milky sap. This is poisonous and makes the entire plant poisonous. It has been used medicinally as a laxative. The plant has also been used to produce a dark tan to black dye.
The name cannabinum refers to the hemp qualities of the plant. Pioneer women would take the stems and rub them, twisting them in the process to make thread said to be stronger than cotton thread. These fibers were used for twine, nets, fabric and bowstrings.
Butterflies like the flowers and the plant flowers for several months. The plant is used for butterfly gardens but must be restrained or it will spread and overwhelm the entire area. It is drought tolerant and not very fussy about soils.