Picnomon acarna (L.) Cass.

Seedling

Cotyledons large, 16-20 x 9-12 mm, oblong, firm, with visible veins, petiolate, glabrous. First leaves rosette-shaped, simple, elliptic-lanceolate, toothed-spiny on the margins with characteristic yellow spines, bristling with coarse hairs, attenuated in the petiole. The hypocotyl axis is short. Dark green seedling.

Adult plant

Picnomon acarna is an annual, very thorny, upright plant with no milky juice. Stem branched, winged, woolly pubescent, up to 70 cm high. Leaves alternate, leathery, oblong-linear, pennatifid, with lobes terminated by golden-yellow spines, 20 mm long; upper leaves sessile, scurved, very decurrent, upper surface covered with whitish woolly hairs; upper ones involucral. Capitula ovoid, 15-30 mm long, sessile, grouped in terminal glomerules of 2-5, rarely axillary. Florets pink, few and fleeting, all tubular, 14-18 mm long, ending in 5 lobes. Involucral bracts tomentose, very spiny, ending in a spine pinnate at the base. Achenes narrowly ovoid, 4-5 mm long, more or less flattened into 2 convex faces with spaced, ochre-colored concolorous striations, surmounted by a deciduous pappus of unequal feathery bristles, fused into a ring at the base.

Origin

Picnomon acarna is native to the Mediterranean-Irano-Turanian region.

Worldwide distribution

Introduced to northern Europe (Sweden, Finland) and southern Australia.

Algeria: Fairly common in the Tell region.