Piedmont Gardener

Camphorweed

I only learned about Camphorweed (Pluchea odorata) a couple of years ago when one of the horticulturalists at the North Carolina Botanical Garden offered me a plant she had “edited out” of a walkway. The medicinal smell of the leaves intrigued me, and the just-expanding inflorescence looked interesting, so I took it home and planted it on the active floodplain beside the perennial creek that borders our property. It is not a knock-your-socks-off plant; it doesn’t have the wow-power of a blooming ironweed covered in butterflies or the landscape-dominating form of Joe-Pye Weed. But I like that about this plant. A landscape full of nothing but “glam-plants” is overwhelming to my eye, and the discovery of the understated beauty of a plant like Camphorweed delivers its own special magic.

This annual has other common names. Stinkweed, like the name Camphorweed, refers to the smell of the leaves. When bruised, they emit a distinctly medicinal odor, to my nose, not unlike the ointment my mother spread on my chest before bedtime when I was sick with a childhood cold. As you probably guessed, that pungency protects the plant from deer predation.

The other common name for this plant is Saltmarsh Fleabane, which refers to this annual’s tolerance of soil in or near brackish water, and the “fleabane” portion likely refers to the plant’s use as a deterrent for fleas and other pest insects. Although the plant prefers moist habitats, I have found it to be resilient in much drier soils than I expected, and it tolerates light conditions from shade to full sun.

I know all this because that one plant given to me bloomed prolifically and then set seed.  Individual flowers in the pink-lavender inflorescence morphed into fluffy light-brown-to-tan seeds that wafted all over my yard on autumn breezes. The following spring, I discovered Camphorweed plants popping up in a number of spots. On the floodplain, plants intermingled with a growing population of Cardinal Flowers, and in the wetter spots, Lizard-tails and Jewelweeds. But some seeds managed to float up the hill to my pollinator garden beds, where they bloomed as happily as they did on the floodplain.

In my yard, mature plants averaged heights between one and two feet. As you might expect, a plant with leaves that smell like medicine has been used that way by a number of cultures. Solutions using the leaves have been used as antiseptics; a tea of leaves and stems has been used to treat menstrual cramps, stomachaches, headaches, inflamed gums, and even to dispel “bad air” brought on via witchcraft. Recent studies show that compounds in the plant appear to disrupt cancer cell growth and may also speed up wound healing. As is true of all plant-based home remedies, you should always proceed with great caution when trying them out, because you can never know the concentration of curative compounds in a given plant. I can tell you from personal experience that simply crushing a leaf and inhaling the scent deeply is a great way to clear a stuffy nose.

Seeds of Pluchea odorata

I am delighted that this annual native has made itself at home in my landscape. It is not aggressive, and because it is an annual, simply removing/relocating it is all the control you need to exert to prevent overenthusiastic spreading. Most of the pollinators I saw on its flowers were tiny flies and a number of ants, but given the amount of fluffy seeds the plants produced this fall, the flowers were definitely being pollinated.