Prickly Sowthistle; Rough Sowthistle
Introduced annual forb to 1.5m tall. Leaves basal and alternating up the stems, 4-20cm long, 20-70mm wide, flat, hairless, lobed, the margins toothed and prickly. Stem leaves with rounded basal lobes. Flowers yellow, with many ‘petals’. Flower heads oval to top-shaped, in groups at the tops of the stems. Sonchus asper ssp. glaucescens in NSW. Sonchus asper ssp. asper in SA. Subspecies of Sonchus asper are no longer recognised federally.
Differs from Sonchus hydrophilus in that the edges of the leaves are spiny.
Differs from Sonchus oleraceus in that the leaves are stiff and leathery, green and glossy.
Description and photo in GM Cunningham, WE Mulham, PL Milthorpe and J H Leigh (1981 and later printings) Plants of Western New South Wales page 717
PlantNET description as Sonchus asper ssp. glaucescens: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Sonchus~asper