Cosmos sulphureus Cav.

Annual herb to 1 m tall; stems slender, branching, erect, slightly quadrate, glabrate but with a few scattered, large whitish hairs. Leaves to 15 cm long, 2-or 3-pinnatisect, the segments acuminate and aristate-tipped, to 3-5 mm broad, glabrous or with a few stout hairs; petiole slender, angled, much shorter or wanting in the upper leaves, often hispid-ciliate at the expanded base. Inflores-cences of one or more heads arising at terminal nodes; peduncles slender, to 15 cm long, apically narrowed, one or more leaflike bracts sometimes alternate along its length. Heads radiate, showy orange, to 5 cm across; outer involucral bracts ca. 8, herbaceous, slender, 5-7 mm long, drying basally striate, the inner bracts membranous-scarious, broader and longer than the outer bracts, drying without striations; paleas resembling the innermost involucral bracts but narrower, partly enfolding the floret; ray florets ca. 8 (a second series present in some horticultural forms), the corolla yellow or orange, 15-20 mm long, the limb obovate, apically 3-denticulate, longitudinally sulcate, sparingly pilose dorsally, minutely papillose-puberulent basally on the ventral surface, the tube 1-2 mm long, the ovary rudimentary; disc florets numerous forming a cylindrical, apically rounded disc, the corollas cylindrical, 7-12 mm long, the tube not demarcated from the limb, the apical lobes narrowly obtuse, ciliate on the inner surface, the anthers yellow, ca. 3 mm long, the bases acute or sometimes subauriculate, the filaments inserted near the bottom of the corolla tube, flattened, densely ciliate, the style branches yellow, pilose, the appendix slender, elongate, the ovary cylindriform, slightly expanded basally, the angles with short ascending hairs. Achenes black, ca. 20 mm long, slender, slightly curved, sharply angled, somewhat compressed, the upper 1/3 narrowed into a linear, ascending-strigose beak terminated by 2 porrect, retrorsely strigose bristles 3 mm long.

A tropical plant. It grows best on light well-drained soil. It needs an open sunny position. It is drought and frost resistant. It needs a temperature above 5°C to grow. It Vietnam it grows up to 1,200 m above sea level. In Argentina it grows below 500 m above sea level. It suits hardiness zones 7-11.

The leaves are eaten raw or cooked. They are used as a spice or flavouring. They are rolled in rice paper with meat, fish or other vegetables.

It is grown by seeds sown directly into the site where they are to grow.