Obscure white Teasel

Today I finally stopped and collected a specimen of a plant that has had me stumped for several years. It is a Teasel with white infloresence that I have been unable to find in any of my field guides, but at last I made an ID. It is Dipsacus laciniatus, an obscure Teasel that occurs in only some 125 counties nation-wide, and I happen to live in one of the five Virginia counties in which it is found. (It is very common locally) I am posting this in case others have been frustrated in IDing this roadside plant because of non-inclusion in many field guides. http://davesgarden.com/guides/pf/go/86012/

This is labeled as "Introduced" on this web site:

http://www.biol.vt.edu/digital_atlas/index.php?do=plant&plant=572&search=Dipsacus+laciniatus

I did not know that! Anyone know where it was intorduced from and when?

neat find greenthumb

According to the Wisconsin DNR: "The common and cut-leaved teasels are European plants introduced to North America in the 1700's."

Reading from my copy of "Weeds of the North Central states" book: Teasel, Dipsacus Sylvestris...Flowers lilac or white... Gives distribution map covering all of Ohio, Ind, lower 1/2 of MI and Ill. Book is dated 1981. It must be spreading north. I can find some just south of my house now.

Gasrocks - I am suprised that "Weeds of The NMorth Central States" lists Dipsacus sylvestris as having flowers of lilac or white. All of my field guides as well as a number of other sources I've checked cite only lilac, lavender etc. The Teasel I posted about is a different species from Dipsacus sylvestris. Here is a scan of a Dipsacus sylvestris specimen I made the same day as the one above. Note the striking difference in leaf attachment to the stem.