Massive Mystery Plant Identified

Since the biggest mystery plant in my garden is now approaching 7 feet tall, I decided that one of my goals for the weekend had to be getting it identified and making a decision about what to do with it. It's not an unattractive plant, loosely shrubby with small purple flowers. My cat, Linus, loves to hang out underneath it.

But it drops seed pods constantly, far more than I can keep up with, and it isn't actually one plant in this corner, it's several. It's like seeing enemy forces on the horizon in ever-increasing numbers.

So I pruned off a branch and headed over to my favorite nursery in Alameda, Thomsen's Nursery, to ask for help. They immediately identified the genus--Solanum--and warned me that it was in the same family as nightshade and probably poisonous.

When I got home, I checked the Sunset Western Garden Book and the Internet and was able to narrow it down further to Solanum aviculare, also known as Kangaroo Apple. It's described as an evergreen shrub, native to Australia and New Zealand, that grows fast to 6-10 feet (I can testify to that!). The flowers and foliage are indeed poisonous, although it apparently has edible, though not necessarily tasty, fruit in the fall. And this is really interesting--it is used in the pharmaceutical industry as a source of steroids. I believe it. This plant acts like it's on steroids--pumped up and aggressive.

So once again, I'm faced with the question: Does it stay or does it go? I think I already know the answer, but Linus isn't going to like it.