Flora of New Zealand Series

Annual to perennial herbs, rarely shrubs or trees. Latex 0. Lvs alternate, usually spiny. Capitula usually homogamous; all florets tubular, ⚥, or sometimes outer florets radiate, sometimes ♂ or neuter. Involucral bracts usually with a spinous or membranous apical appendage. Receptacle bristly or hairy, or glabrous; scales present or 0. Anther bases caudate. Style with branches appressed or diverging only at apex, thickened beneath the union of the branches with a circular swelling bearing a bristly collar. Pappus of bristles, scales, or plumes, usually in several rows, elements often united into a ring at base.

SYNOPSIS

• A. Subtrib. CARDUINAE. 
• • Detachment scar of achenes straight. Pappus elements of ± equal length and form:
  • ArctiumCarduusCirsiumCynaraOnopordumPtilostemonSilybum
• B. Subtrib. CENTAUREINAE. 
• • Detachment scar of achenes concave. Pappus elements of 2 types; outer rows numerous, all similar, increasing in length towards the centre; innermost row single, often morphologically distinct, often much reduced:
  • AcroptilonCarthamusCentaurea

66 genera, 2410 spp., mostly Eurasia, also Australia and the Americas.

Many genera of Cardueae are thistles, spiny-leaved herbs with spinous involucral bracts. Most true thistles belong in this tribe, although the name thistle is applied to other plants (e.g. sow-thistle, Sonchus, trib. Lactuceae). The Cardueae has often been referred to as Cynareae, but that name is illegitimate. Echinops, traditionally often treated with the Cardueae, is here treated under a separate tribe, Echinopeae, following Dittrich, M., in V. H. Heywood et al. (op. cit.).

Dittrich (loc. cit.) provided a systematic review of the tribe. Healy, A. J., Identification of Weeds and Clovers ed. 1 (1970), provided a practical account of the spp. of thistles and thistle-like weeds in N.Z.

Achenes of representatives of each subtribe are illustrated in Fig. 32. Plants and capitula of characteristic spp. are featured in Plate 9.

Fig. 32. Cardueae, achenes. A Cirsium vulgare; B Carduus nutans; C Carthamus lanatus; D Centaurea nigra; E Centaurea solstitialis. © All rights reserved. [Image: 4X4Q]