Scientific Name:
Lactuca virosa L.
Vernacular Name(s):
Acrid lettuce

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.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]


Flowering: (Aug.)–Dec.–Feb.; Fruiting: (Aug.)–Dec.–Feb.