Jun 02 2013
Long ago I learned, “Look but don’t touch.” This is a good rule of thumb when you’re not sure of what you’re looking at outdoors.
Yesterday I attended the Wissahickon Nature Club’s annual picnic at Mingo Creek County Park. At Wissahickon we’re all curious about nature. Some know birds best, some know plants, others know insects, so our outings are really informative. We examine everything, we teach each other, we look up the mysteries, and we all learn something.
Yesterday I learned about cow parsnip, a large plant that I had largely ignored. Here I am standing next to it. Notice that I’m not touching it. That’s a good thing if you’re not sure what it is!
Cow Parsnip (Heracleum maximum) is a native member of the parsley family. Though it’s a good plant and was used medicinally by Native Americans, it looks a lot like giant hogweed (Heracleum mantegazzianum), an invasive plant from Eurasia that’s so toxic it causes nasty skin rashes if you merely brush against it. With so many botanists in the group I knew this plant was safe.
The umbels of cow parsnip and giant hogweed look similar to the untrained eye. The flower is large and pretty.
The real difference between the good plant and the bad one is that the stems and sheaths of cow parsnip are green.
This green sheath is good (cow parsnip). The bad one, giant hogweed, has purple splotches on its stem and sheaths and thick hairs at the leaf joint (but who wants to get that close!). Interestingly, poison hemlock, another bad member of the parsley family, also has purple splotches on its stem.
Rule of thumb in this case: green is good, purple is bad.
But the real rule of thumb is Look But Don’t Touch.
…which explains why I’m overdressed on a hot day. I always wear long pants, long sleeves, a hat, and sunscreen outdoors. You can’t see my ankles but my socks are pulled over my pant legs to keep out ticks. This outfit saves me a lot of itchy aggravation later.
We may look odd, but ask us about cow parsnip and we’ll tell you, “This one is OK.”
p.s. See the Comments for further discussion.
(photos by Dianne Machesney)