Jul 3, 2014
PLANT PROFILE: Dogbane
I have been eying this handsome plant growing in a vacant lot on the corner of West 146 Street and Frederick Douglas Blvd. It looks a bit like milkweed and I have milkweeds and butterflies on my brain a lot lately. The plant has clusters of tiny greenish white flowers and narrow, smooth-edged elliptical leaves, growing on opposite sides. Like milkweed, it oozes milky sap when broken. However, unlike common milkweed, it branches and the stems are deep red.
It is a North American native perennial called Apocynum cannabinum. Common names are Indian Hemp, Dogbane or Hemp dogbane and though it is related to the common milkweed, it is not a milkweed. Bummer! Monarch butterflies feed exclusively on milkweeds and while some butterflies may sip the nectar of dogbane flowers, the monarch larvae do not flourish on dogbane leaves.
Dogbane is tough as it grows despite the annual weed-killing fabric and coarse gravel that is laid in the lot. A few other plant species like mugwort and wild chicory manage to pop up but dogbane dominates the space. I pulled then dug some up and found that they grow like common milkweed with horizontal rhizomes.
Plants in a shadier area are much greener. They benefit from less moisture-loss but alas, they do not flower. Still very attractive.
Native American tribes made thread and rope from the tough fibers along the stems of Apocynum cannabinum, hence the common name, Indian hemp. The name 'Dogbane' may have stemmed from the highly toxic glycoside substance present in all parts of the plant. Small amounts have reputedly killed horses when accidentally included in dried hay. It has also killed and sickened sheep and dogs (which dog is silly enough to not detect poison in a plant). Dogbane may also have gotten the name from its use in treatment of mad-dog disease. Also, the milky substance that leaks from any broken part of the plant may be a reminder of foam, as in the foaming mouth of a mad dog. It was also used to induce vomiting, bringing to mind phrases such as 'as sick as a dog'. It is possible that the plant literally was the bane of dogs. Toxins in dogbane are currently used in drugs for cardiac treatments.