Wild Turnip, Mediterranean Turnip, Long-fruited Wild Turnip
Introduced annual forb to 60cm tall. Leaves basal and alternating up the stems, 6-30cm long, flat, bristly, deeply lobed. Stem leaves reducing to linear. Flowers pale yellow fading to white, with 4 petals, in open groups at the tops of the stems.
Description and photo of flowering plant in G.M. Cunningham, WE Mulham, PL Milthorpe and J H Leigh (1981 and later printings) Plants of Western New South Wales pages 319-20
eFlora of South Australia fact sheet: http://www.flora.sa.gov.au/cgi-bin/speciesfacts_display.cgi?form=speciesfacts&name=Brassica_tournefortii