SOUTH AFRICAN DAISY
This is another weedy Senecio. It is tall (up to 1.5m high), with multiple stiff stems. These can become quite woody. Yellow daisy-like flowers appear in summer in groups at the top of the stems. It is really easy to identify this Senecio because where the leaves join the stem, they keep going down that stem to form wings (see 3rd photo above). So when you run your hand down the stem you can feel these as flappy bits.
The leaves themselves are lance-shaped, and toothed. They are darker on top, pale underneath. The 4th photo compares the leaves of the weed (on the right) with the leaves of Senecio odoratus (left) (see Plant of the Month).