This appears to be happy in the trunk of a potted palm.
I can only guess how it got there.
There is a pot of it growing ~4 ft away....I think the seeds get ejected when
the pods are ripe(?) Makes a nice potted plant, volunteer, or ground cover.
BTW, here is a 1600x1240 (800 kb) image if anyone would like to use it for a background. ;)