Flora of New Zealand Series

wall lettuce

Glabrous perennial. Stem usually single, erect, not branched or branching above, finely grooved, (20)-50-100 cm tall. Rosette and lower stem lvs petiolate, 7-20 × 3-10 cm, lyrate-pinnatifid with a large triangular or reniform ternatifid coarsely toothed terminal lobe and 1-3 pairs of small ovate-hastate coarsely toothed lateral lobes; hydathodes prominent at tips of teeth; lamina thin, bright green above, pale and glaucous beneath. Upper lvs similar, with petiole becoming broadly winged and amplexicaul-auriculate at base; uppermost lvs not divided, linear to oblong, amplexicaul. Infl. diffusely paniculate. Capitula numerous, narrowly cylindric. Outer involucral bracts 2-4, very short, ovate to lanceolate, 1/10-? length of inner bracts. Inner involucral bracts linear, strictly erect, often purplish, 5-7 mm long; margins scarious. Receptacle areoles with raised glabrous margins. Florets 11/2× length of involucre; corolla pale yellow. Achenes usually 5 or fewer, dark brown to black, 10-ribbed, fusiform, flattened, very finely scabrid, shortly beaked, 3-4.5 mm long. Pappus bristles in 2 ± unequal rows, fine, white.

N.: Coromandel southwards; S.: throughout; St.

Europe, Asia Minor, N. Africa 1899

Forest and scrub, forest margins, roadsides, stream beds, pasture, lakeshores, almost always in shaded sites.

M. muralis is likely to be confused with Lapsana communis, but may be distingished by its glabrous lvs, 5 or fewer florets, and beaked achenes with a pappus. M. muralis superficially resembles Senecio wairauensis (Senecioneae), but S. wairauensis is distinguished by its heterogamous capitula, thicker lvs with more rounded teeth, its paler, sparsely papillate, beakless achenes, and watery juice. M. muralis has also been referred to in N.Z. as Lactuca muralis.