Centaurea calcitrapa L.
star thistle
Biennial. Stems erect, weakly ribbed, branched, (15)-30-60 cm tall, with sparse to dense multicellular hairs. Lvs not decurrent on stems, with sparse to dense multicellular hairs; lower lvs deeply pinnatifid, 5-10 × 1.5-4 cm, with oblong to lanceolate or linear, toothed or lobed segments; upper lvs becoming smaller, sometimes simple. Capitula shortly stalked, not clustered. Involucre ovoid to cylindric, 5-8 mm diam.; outer and middle bracts elliptic to oblong, not veined, glabrous; appendages spreading, not covering bracts, spinous, slightly narrowed at junction with bract, not decurrent on bract; terminal spine 15-20 mm long, yellowish; lateral spines 2-3 on each side, 2-3 mm long, all at base of terminal spine. Florets pink to purple, the outer slightly radiate. Corolla with glandular papillae. Achenes c. 3 mm long, glabrous; pappus 0.
N.: Northland, East Cape, King Country, Wanganui, Hawke's Bay, Manawatu; S.: Marlborough, Canterbury.
Mediterranean 1855
Roadsides, pastures, waste land.
FL Nov-Apr-(May) FT Nov-May.
Two other Centaurea spp. in N.Z. have spinous appendages to the bracts: C. melitensis and C. solstitialis both differ from C. calcitrapa in their yellow florets and lvs decurrent on the stems.
