Silybum marianum (L.) Gaertn.
variegated thistle
Annual or biennial. Stems branched above, ridged, with sparse mealy hairs at least above, 0.5-2 m tall, not winged. Lvs elliptic to lanceolate, lyrate-pinnatifid to pinnate, sinuate, coarsely dentate, green with conspicuous white markings along veins, (10)-20-60 × (5)-10-30 cm, with sparse short mealy hairs on lamina, and sparse long tangled multicellular hairs on midrib; base amplexicaul, auriculate, with very spinous margins; prickles marginal, yellowish, spreading, 5-12 mm long. Capitula ovoid, erect, 4-6 × 5-7 cm, solitary, terminal and pedunculate, and also sessile in axils of uppermost lvs; peduncles with appressed cobwebby tomentum. Involucral bracts sparsely covered with short mealy hairs; margins with sparse cobwebby hairs. Outer bracts leaflike, obovate with spinous apex and margins. Middle bracts oblong; appendage ovate, subulate, with spinous margins and a long spreading to recurved apical spine. Inner bracts lanceolate; appendage becoming linear-lanceolate, entire. Corolla reddish purple, 20-28 mm long; lobes unequal, 4-6 mm long. Anther filaments joined at margins into a tube which encloses the basal appendages of the anthers. Style exserted 1-2 mm beyond corolla lobes. Achenes brown or black-streaked, obovoid, weakly transversely flattened, smooth, c. 6 × 3 mm; outer pappus bristles scabrid, c. 15 mm long; inner hairs very fine.
N.: Northland, Auckland, Waikato, Bay of Plenty, East Cape, Volcanic Plateau, Wellington; S.: Marlborough, Canterbury, Otago, Southland; Ch.
Mediterranean, S.W. Europe 1869
Roadsides, pastures, gardens, waste land.
FL Nov-Jan-(Feb) FT Dec-Mar.
Poisonous (Connor 1977).
S. marianum has also been referred to in N.Z. as Carduus marianus.
