Annual herb to 1.2 m tall, glabrous. Stems erect, branched. Leaves and leaflets linear to linear-lanceolate, to 10 cm long, margins entire or once or twice divided, shortly petiolate. Capitula numerous in corymbs, to 3 cm across, long-stalked; spring to early autumn. Ray florets yellow, red-brown at base. Disk florets dark red. Achenes ovate, 2-3 mm long, wingless. Pappus absent.

N America

 

C. maritima (Nutt.) Hook. f. from W USA is a spreading perennial to 80 cm tall with linear leaflets, capitula to 8 cm across, all florets yellow and achenes with narrow hairy wings and a pappus of 2 barbed bristles.

C. rosea Nutt. from E North America is an erect annual or perennial to 60 cm tall with linear leaves or leaflets, capitula to 2.5 cm across, rose pink ray florets and smooth wingless achenes without a pappus; 'American Dream' and 'Nana' are listed.

C. verticillata L. from E USA is an erect perennial to 90 cm tall with at least some leaves palmately divided, capitula to 5 cm across, all florets yellow and warty wingless achenes with a pappus of 2 short bristly teeth; 'Moonbeam' grows to about 50 cm with lemon yellow flowers, and 'Zagreb' to 30 cm with golden flowers.

Source: Jeanes, J. (2002). Asteraceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.