Lactuca virosa L.

Annual or biennial. Stem erect, branching above, finely grooved, with patent pale spines up to 4 mm long, especially below, (50)-100-280 cm tall. Lvs green; rosette and lower stem lvs tapering to base, with spinous bristles beneath on midrib and often on secondary veins, 8-25-(35) × 5-18 cm, deeply runcinate-pinnatifid to undivided; margins dentate to bristly-ciliate, usually sinuate. Upper lvs often with spinous bristles on midrib, oblong to obovate, often triangularly 3-lobed at apex, with oblong to rounded amplexicaul auricles at base. Infl. diffusely paniculate. Capitula numerous, cylindric. Involucre (11)-13-15 mm long; bracts imbricate, suberect to reflexed at fruiting; outermost bracts ovate to lanceolate, subacute, ?-1/2length of innermost bracts; inner bracts lanceolate to linear, subacute. Florets c. 11/2× length of involucre; corollas erect to erecto-patent, yellow. Achenes very dark brown or black, 5-8-ribbed on each face, obovate, flattened, finely spiny distally on ribs; body 4-5 mm long; beak pale, c. = body. Pappus fine, white.

Grassy places by roads, canals etc and on banks near the sea, usually on calcareous soils.

The plant accumulates lactucarium towards flowering which is mildly narcotic. The leaves although bitter are added to salads.

Can be grown by seedlings.