Dec 29 2010
Spreading Dogbane (Apocynum androsaemifolium) is one of my favorite winter weeds because it’s easy to identify and has such a cool name.
It’s a shrublike, woody perennial that stands one to four feet high with widely branching stems. In snow cover its seed pods stand out. Dark brown, three to eight inches long, and very narrow, they split open lengthwise to reveal seeds with fluffy fiber tufts similar to milkweed.
Shown above are two winter views of its pods. On the left the unopened pods dangle in pairs from the stem. They’re as long as your hand, or longer. On the right the pods have burst open.
Because dogbane and milkweed are related, they share another characteristic as well: both have milky, poisonous sap. That’s how dogbane got its unusual names. Dogbane means “dog poison,” Apocynum means keep “away from dogs.” Why all the focus on dogs? I don’t know. It’s poisonous to people and livestock, too.
In winter dogbane is easily confused — at least by me — with closely related Indian Hemp, so named because its tough fibrous bark was used by Native Americas to make rope and twine.
Look for spreading dogbane in fields and thickets. If you’re in a marsh or at the shore, the plant may be Indian hemp.
(photos by Marcy Cunkelman)