Shirley, I've got a black hollyhock that I cut the seedpods off of yesterday. t-mail me your address and I'll send you some. I can't guarantee that they'll come true from seed though, since I've never grown any of them. The plant is between 7 and 8 feet tall. If I can find the name, I'll let you know. I'd love some pink!
Edited to add that I found the package (bought bareroot), and it's just listed as black. Sorry I don't have a name to put on it. Also, I just noticed that you're looking for doubles. Mine is a single, though I noticed a flower or two that looked a little more double to me.
