Flora of New Zealand Series

Annual to perennial herbs, rarely shrubby. Stems winged or not. Hairs long and multicellular, short and glandular, and cobwebby to lanate. Lvs alternate, sessile, decurrent on stems or not, simple, entire to 1-2-pinnatisect, not spinous, often with minute glandular depressions or pits on surface. Capitula ovoid or cylindric or globose, solitary or clustered. Involucral bracts in several series, hairy or glabrous, usually with an apical appendage; appendages spinous or membranous, pectinate, fimbriate, or lacerate, decurrent on the bract margins or narrowed at junction with bract. Receptacle ± flat; scales bristly. Inner florets ⚥, tubular; outer florets neuter, usually radiate. Corolla glabrous or with glandular papillae, 5-lobed, purple, pink, blue, yellow, or white. Anthers tapered to a rounded apex, with short, tapering basal appendages; filaments bearded. Style branches linear, erect, appressed or diverging slightly at apex. Achenes cylindric to clavate, glabrous or finely pubescent, smooth; achene insertion oblique; pappus sometimes 0, usually of (2)-several rows, scale-like to bristly, scabrid to plumose; outer rows (1)-many, all similar, increasing in length towards the centre; innermost row single, usually short, connate or free to base.

600 spp., Eurasia, N. Africa, temperate N. and S. America, Australia. Naturalised spp. 10.

The bract appendages of Centaurea provide many of the characters used in classification and identification of the spp. (Fig. 33). Unless otherwise stated descriptions and keys refer to middle involucral bracts. Spines and recurved appendages are not included in measurements of involucre diameters.

Fig. 33. Centaurea, middle involucral bracts. A C. cineraria; B C. cyanus; C C. jacea; D C. maculosa; E C. calcitrapa; F C. melitensis; G C. montana; H C. nigra; I C. scabiosa; J C. solstitialis. © All rights reserved. [Image: 4X4R]