October 15, 2009
Dear Mr. Dennis,

First, I enjoy your magazines. Not to be a pedant (well, yes!), I noted the item on giant hogweed in the August issue of Horticulture Review. It is described as “known in some areas as cow parsnip.”

You may need to clarify this. Most LO members will recognize common weeds, but unless they go hiking and are interested in wildflowers, they may never have seen real cow parsnip. That plant (Heracleum lanatum or sometime H. maximum), although in the same genus as H. mantegazzianum, is a very widespread native. While a few people get a rash from it, it’s considered innocuous, and is quite a sight to see, especially when bears are eating them out west.

I’d hate to see people going out with flame throwers destroying a handsome wildflower. So, a side-by-side set of photos might be useful (both are on the ontarioweeds.com website), so that if some LO firms get calls from customers to eradicate the aliens, hopefully they’ll be able to distinguish them.

The real hogweed is pretty scary. It’s even showing up here in Thornhill, so bring on the flame throwers.

Professor Richard A. Jarrell
Division of Natural Science,
Faculty of Science and Engineering,
York University,

Cow parsnip