Carthamus leucocaulos

Plants 30-100 cm, herbage glabrescent. Stems rigidly erect, shiny white, often much-branched distally. Leaves basal and cauline; basal often absent at anthesis, petioles winged. blades pinnately divided into 6-8 pairs of narrow lobes; cauline spreading or recurved, lanceolate to ovate, rigid, clasping, 3-7-veined from base, margins pinnately divided into 2-3 pairs of short, spine-tipped lobes, apices spine-tipped. Involucres ovoid, 10-13 mm, usually ± glabrous. Outer phyllaries ascending or ± spreading, very shiny, 40-50 mm, 2.5-3.5 times as long as inner, terminal appendages spreading to ascending, spiny-lobed, prominently spine-tipped. Corollas pink or pale purple, 13-17 mm, throats abruptly expanded; anthers white or pink with purple stripes; pollen white. Cypselae brown, 3-5 mm, outer roughened; pappus scales 5-7 mm. 2n = 20 (Greece).

Flowering summer (Jun-Aug). Disturbed sites; 0-200 m; introduced; Calif.; Europe (Greece, islands of Aegean Sea).

Between 1969 and 1990 an infestation of this noxious weed was documented in Sonoma County. Efforts to eradicate it were apparently successful.