Friday, July 28, 2006

Burdock

It seems that each year I forget, from the year before, what the differences are between Common Burdock (Arctrium minus)and Great Burdock (Arctrium lappa). In the photos below the Common is on the left and the Great is on the right.



In general, Great Burdock is larger. The flowers are larger and on longer stems. The Great Burdock grows 1 to 2.4 metres (3 to 8 feet) tall and the Common grows .6 to 1.2 metres (2 to 4 feet) tall.



The stems of the Great Burdock are solid with deep grooves while the Common Burdock has hollow stems and shallow grooves.

Of course, just to make things more difficult, the two can and do hybridize. I am not sure how to tell the hybrid. Does anyone else know?

3 comments:

romunov said...

Arctium? I have A. minus in my herbarium. I didn't take the root, though. The plant was just too big. I hope that won't be a problem for the assistant evaluating (the herbarium). :D

As a side note, we call A. lappa "common" burdock, while A. minus is "little" burdock.

Ontario Wanderer said...

I read, someplace, that the root can go down a metre or more. I think plants like Burdock are very hard to press and keep on herbarium sheets. The herbarium where I volunteer has started adding to the records with photography.

Common names are a dime a dozen in almost every language.

romunov said...

What is the phrase for "a basket of flowers" common for Asteraceae and other families?