I need to know the name of this sunflower, and if it is native to North America, especially to the north East - i am in Southwest Ontario. Leaves are opposite and rough to touch on both surfaces.

In the past i have found it to be quite agressive, so i now restrict it by removing the seed heads and sometimes using RoundUp. I try to keep just a few of these.

Pics of flower, buds, and leaves ...

And my recent success - with Biennial Gaura. I planted 6 of these about 3 years ago. Beautiful! They grew to well over 6' tall. I gathered and spread the seed, and none came up the next year. This year they are all over. At least 2 or 3 dozen. Up to 9 or 10 feet tall.

So i guess this is the "Biennial" characteristic? What happens next year?

Here is a pic - late in the season so they are all leaning over now; not as spectacular as when they were straight up.

I put a link to a video of my "meadow", which is really a Savannah. I did not know that when i started it in 1998, and the name meadow seemed romantic to me at the time.

Thanx,

Mick

Consulting my Tallgrass Prairie Wildflowers and Peterson's i see four Silphiums. It is clearly not either Prairie Dock or Compas Plant - i have those also in my meadow; and it does not fit the description of the Cup Plant.

However, it is a perfect mate to the Rosin Weed, S. Integrifolium.

BTW, my meadow is ~31' wide x ~100' deep, so about 3000 sq ft. Here is a video of what it looks like after Spring preparation. Quite a difference from mid-summer ...

Thank you.