I don't know either but I've also started it this year from Holubec. (The seedlings, as they approach about 1/2 " diameter are compact, upward-cupping(?), hairy little rosettes, more similar to Darren's photo than to the looser ones in Diane's photo. Would a photo of them be helpful?)
In the Holubec catalogue, he likens the foliage to A. villosa, if that is helpful.