Slender Groundsel, Groundsel
Annual forb to 50cm tall. Leaves alternating up the stems, sometimes with cordate bases and mildly stem clasping, 0.8-10cm long, 3-25mm wide, linear to flat, sparsely hairy, edges entire, toothed or lobed. Flowers green, with 4-8 tiny yellow 'petals'. Flower heads bell-shaped, in groups at the tops of the stems.
Differs from Senecio productus ssp. productus in that it has narrower flower heads (1-2mm, occasionally to 2.5mm, diameter), with fewer green bracts on the backs of the flower heads (usually 7-10, occasionally 5-6 or 11-13), and small 'petals' (1-2mm long).
The description above is mostly based on the description in Thompson, I.R., (2005) Taxonomic studies of Australian Senecio (Asteraceae) 4. A revision of Senecio glossanthus and recognition of an allied species with long ligules. Muelleria 21: 6-7, Fig 1a (flower structure page 5), Fig 2a (map page 8), Fig 3 (photo of dried specimen page 9)
Description and photo in G.M. Cunningham, WE Mulham, PL Milthorpe and J H Leigh (1981 and later printings) Plants of Western New South Wales page 677