Flora of New Zealand Series

prickly sow thistle

Annual or biennial. Roots tap and fibrous. Stem erect, usually simple, finely grooved or ribbed, glabrous, (15)-20-60-(180) cm tall. Lvs firm-textured, ± shiny, usually green or rarely glaucous above, paler to ± glaucous beneath, glabrous, lanceolate to oblanceolate or obovate; margins sinuate-dentate with prickly-spinose teeth. Rosette and lower stem lvs tapering to expanded auriculate base, (4)-10-20-(40) × (1.5)-3-6-(15) cm, pinnatifid to c. 1/2 way to midrib or rarely not lobed; lobes recurved to spreading, triangular to lanceolate. Upper lvs pinnatifid or not lobed, narrowly triangular to subulate, with rounded amplexicaul auricles at base. Infl. cymose to umbellate; capitula few to many. Involucre 10-15 mm long, turbinate to cylindric; bracts imbricate, reflexed at fruiting, glabrous or rarely with tangled white short branching hairs and sparse long pale glandular hairs. Receptacle glabrous. Florets 11/2× length of involucre; corolla tube > ligule; ligules spreading, yellow. Achenes elliptic, pale brown, strongly flattened, 2.5-3 × 1-1.6 mm, 3-ribbed on each face, winged; spaces between ribs smooth; ribs and edges of wings smooth or finely scabrid. Pappus fine, white, c. = involucre.

N.; S.: throughout; St.; Ch., Ant., A., C.

Europe, N. Africa, N. and W. Asia 1870

Gardens, arable land, waste land, roadsides, coastal sand and talus, pasture, damaged forest, lake shores.

S. asper differs from S. oleraceus by its glossy lf upper surfaces, rounded appressed auricles, sinuate-dentate lf margins with prickly teeth, and flattened, winged, smooth achenes. S. asper f. hydrophilus (Boulos) J. Koster was recorded for N.Z. by Boulos, L., in Eichler, Hj., Fl. S. Australia ed. 2, Suppl. (1965, as S. hydrophilus Boulos), but that record was based on specimens of S. kirkii.

S. asper has been recorded in N.Z. as S. oleraceus var. asper. Some very early records are based on material of S. kirkii.