thanks, that is exactly what i was just reading. it doesn't seem to be taking over at all. the former owner of my home was a longtime member of the local garden club and i wouldn't think she would've planted anything in her yard that would be harmful. i just wish she were around to help me identify everything!

Here are the remnants of the bud and seeds from last year. I only found it in one other place on the web, which I've linked. The poster includes a picture of the "bloom," and describes perfectly what happens to it. Maybe the bloom is just green? The other poster never found out what it was. Here is a link that might be useful: Another example elsewhere on the web

Erysimum, aka Wallflower.

It is a carnosa and it will do just fine in that West window! The leaves will lighten, but more light does encourage blooming (however, carnosa is one of those that likes to take it's sweet time to bloom...it could take a couple of years).