Senecio leucanthemifolius Poir.

Seedling

Cotyledons elliptical-oblong, 6-15 x 2-3 mm, distinctly petiolate, glabrous. First leaves ovate to obovate, broad and toothed, with a few hairs on the petiole. The hypocotyl axis is fairly short, 15 mm, greenish to purplish. The seedling is light green and does not produce white latex.

Adult plant

Senecio leucanthemifolius is an annual plant with a rapid biological cycle, upright habit, producing a white latex when broken. Stem is simple, erect or ascending, sometimes subacute, angular, solid, glabrescent and up to 40 cm high. Leaves alternate, slightly (subsp. poiretianus M.) or very (susbsp. crassifolius Batt.) fleshy, irregularly pennatilobed or sinuate-dentate, scarcely hairy, the lower ones obovate to spatulate, petiolate, the upper ones clasping, with scarcely denticulate auricles, becoming subentire. Inflorescence an irregular corymb of capitula. Capitula radiate, 18-22 mm in diameter, 4-8 mm long, with glabrous involucre, and calicule of 10-21 lanceolate-acute bracts, spotted black at the apex. Central florets tubular with yellow corolla, peripheral florets ligulate, sparsely (subsp. poiretianus M.) or strongly (susbsp. crassifolius Batt.) yellow-curled, about 7-9 mm long. Achenes subcylindrical, 2.5-3 mm long, with ribs covered with white applied hairs, pappus with short, white, toothed hairs, deciduous.

Origin

Senecio leucanthemifolius is native to the western Mediterranean.

Worldwide distribution

Introduced in Sweden.

Algeria: Subsp. Poiretianus is common throughout the Tell, while subsp. crassifolius is fairly common on the seashores of the Oran coastal Sahels sub-sector, as well as the Algiers coastal sub-sector.

https://www.gbif.org/species/7624085