Wulfenia carthiniaca has been hanging around for years in my yard... and not doing much. It is native, apparently, to the Austrian and Italian Alps, and to the Baltic region. The common name for this plant is Cow's Footstep... (huh, no wonder it's unpopular. ;D ;D )
http://luirig.altervista.org/schedeit/pz/wulfenia_carinthiaca.htm
http://www.cabdirect.org/abstracts/20103145102.html
Anyway, in 2009, it finally bloomed! 
It declined to bloom again in the following year, however. :( It seems to prefer more moisture than this climate naturally offers, so I'm thinking of moving it into a north-facing, shaded spot somewhere in the current (or future) tufa garden. (It is currently in regular alkaline soil, in part shade - though perhaps a bit more sun than shade, with competition from trees - at the front of a perennial bed.)
Does anyone have any advice on how to grow this plant properly?