Centaurea cyanus L.
cornflower
Annual. Stems erect, ribbed, branched above, 35-100 cm tall, with sparse to dense cobwebby tomentum. Lvs not decurrent on stems, with sparse to dense cobwebby tomentum especially beneath; lower lvs linear-oblanceolate, 8-15 × 0.5-1 cm, entire or minutely and distantly dentate, or with 1-(2) pairs of short narrowly triangular lateral lobes; lamina tapering to long petiole; upper lvs simple, becoming linear, smaller. Capitula not clustered. Involucre globose to campanulate, (9)-10-15 mm diam.; outer and middle bracts ovate to lanceolate, weakly 3-(5)-veined, pubescent or with sparse cobwebby hairs; appendages erect, fimbriate, not covering bracts, membranous, not narrowed at junction with bract, decurrent to base of the bract; fimbriae 7-10-(12) each side, the distal ones black or dark brown, c. 1 mm long, the proximal ones silvery. Florets usually blue, sometimes purple, pink or white, the outer radiate. Corolla eglandular. Achenes 3-3.5 mm long, sparsely pubescent; pappus up to 2.5 mm long.
N.: Wellington (Upper Hutt, Wellington, Island Bay); S.: Westland (Reefton), Canterbury (Christchurch, Opihi R.).
S.E. Europe, Sicily 1875
Shingly waste land, railway yards, roadsides.
FL Nov-Feb-(May), FT Dec-Mar.
C. cyanus is distinguished from other spp. naturalised in N.Z. by the appendages of its involucral bracts, which have flattened, very narrowly triangular fimbriae and are decurrent to the bases of the bracts, and by its usually blue florets. The lower fimbriae are conspicuously silvery. C. nigra may have similar narrow-oblanceolate, entire or 1-2-lobed basal lvs but differs in its pectinate-fimbriate appendages which are markedly narrowed at their junction with the bract, and in its perennial habit.
