Susan thanks. Lots of info on the forum page you reference. The leaves of my plant have the same character as those shown in your last photo, crem3leaves.jpg but larger. You say that is like Cremanthodium ellisii, which it is, but not quite the same as the photos I've found on the web.
If I've mixed up labels, I got these as Cremanthodium arnicoides from the AGS Seed ex, 19/12/2007. I've been assuming I didn't mix things up, hence the useless subject line, in which case they were senecio jacquemontianus SRGC Seed ex 23/1/2008.
Anyway, wonderful to have some help.