Character

Sonchus arvensis

Sonchus asper ssp. asper

Sonchus oleraceus

fruit body appearance

narrowly elliptic to oblong,
ribs close together
and transversely wrinkled

elliptic to oblanceolate,
ribs far apart
and not wrinkled

oblanceolate,
ribs far apart
and transversely wrinkled

pappus bristles

8–15 mm long,
not tangled around fruit body

6–9 mm long,
tangled around fruit body

5–8 mm long,
sometimes tangled around
fruit body