Scientific name: Sonchus arvensis L.
Common name: Sow-thistle
Description
Habit: Perennial, 70-150 cm high.
Stems: Hollow, hairless below but with pedicels covered with dark hairs; with latex, with a creeping rhizome.
Leaves: Alternate, usually pinnatifid with a few, widely-spaced segments; toothed, slightly prickly margins; auricles of the upper leaves short and rounded.
Flowers: Deep yellow, flower-heads numerous, 35-40 mm across, in a corymbose panicle; involucre not closing at the top after flowering; involucral bracts overlapping in several rows; florets all ligulate.
Fruits: An achene, flattened, not beaked, with fine transverse wrinkles; pappus of unbranched, white hairs.
Habitat: Stony sea shores, roadsides, cultivated ground.
Distribution: Very frequent over most of the limestone, occasional elsewhere.
Native status: Native
Of conservation interest: No