American Burnweed, Erechtites hieracifolia:
http://courses.missouristate.edu/pbtrewatha/american_burnweed.htm

Looks like Erechtites hieraciifolia which doesn't flower until much bigger usually (unless it is late in the season). Considered by most to be a weed; very fleshy stems, very easy to pull out.

my first clue as to whether it was a weed .. may have been that it is within inches of the wall.. and probably straight down from the eave/gutter.. where the bird deposited it for you ... or the wind stopped and it fell from the sky ...

ken

Here is a link that might be useful: ah.. yes.. windborne ...