SCENTED GROUNDSEL

(Senecio odoratus)

(Photos: E.Cousins; stems; flower head; leaves)

Senecios come in many forms, and this month we are featuring both a goody and a baddy. Both have clusters of yellow flowers over summer. However, those of the scented groundsel (our goody) don’t have a disc of long petals; the flowers tend to form tubes with a ‘fluff’ of short (4-6mm) petals on top. Also, the leaf shape and colour is very different in our two Senecios. The dull grey-green leaves of the native scented groundsel, Senecio odoratus, are oval-shaped, with a very distinctive vein down the centre. They are quite firm. The edges have fine teeth at the edge (whereas the South African daisy, Senecio pterophorus has larger indentations on the edges). The top of the leaf is fairly hairless, but the back looks like it is covered with fine cobwebs. Where the leaf clasps the stem, the leaf curls in on itself a bit.

The scented groundsel makes a good host plant for the endangered native parasitic plant Orobanche cernua var. australiana (see plant of the month, Jan 2017).

SOUTH AFRICAN DAISY

(Senecio pterophorus)

(Photos: E.Cousins; weed habit; a stem; close-up of wings; leaf comparison)

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 4^th photo compares the leaves of the weed (on the right) with the leaves of Senecio odoratus (left) (see Plant of the Month).