Similar but not quite

I took these pictures in my friend's garden. She says it is Silphium Perfoliatum. To me it looks almost, but not quite, like Helianthus tuberosus (Jerusalem artichoke). Any other suggestions please?

 

Heliopsis helianthoides?
http://www.wildflower.org/plants/result.php?id_plant=HEHE5

 

The leaves don't look perfoliate, so a Heliopsis seems more like it.

http://www.hort.net/profile/ast/silpe/

 

Thanks. The description at http://www.wildflower.org/plants/result.php?id_plant=HEHE5
fits it exactly, and the leaves are definitely not perfoliate, so it must be Heliopsis.