A Gardeners Forum Forums Gardening Reference Gardening in 2007 Somebody must know this one....

Trying to ID this plant on the net is what brought me to this site in the first place, so here goes...

First of all, it was bought at a local botanical garden but may or may not be native to my area.
It grows to be over 6 feet tall and later this summer it will have small yellow flowers that grow atop pencil size stalks. The flowers look like sunflowers except they are about the size of a quarter. The main stalk is square(ish), more of a rounded diamond shape actually, and about 3/4" on each side. It does spread, I started with only one. Where the leaves attach to the stalk it forms a small pocket that holds water.
I know most of what's in my yard by name, but this one eludes me.
Thanks for any help!
John
[img]http://img.photobucket.com/albums/v605/thegreatjps/Ebay%20Photos/97bc9644.bmp[/img]

Is it Silphium perfoliatum 'cup plant' ?
Silphium

WOW! That was fast. I've always lived in the northern Indiana, southern Michigan area and have never seen this plant anywhere other than here and in my sisters garden.
Thanks so much for the help!
John