both seed-raised and vegetatively propagated cultivars are available, varying in the size, colour and shape of the petals. an article in 2017 listed 17 cultivars and seed-raised strains. , "c." "atrosanguineus" 'hamcoec' (trade description ) has the largest flower heads, up to 5 cm in diameter. the variation in flower color from red to black of "cosmos atrosanguineus" and its cultivars results from variation in the amounts of anthocyanins and chalcone present. hybrids with other "cosmos" species are also known in cultivation. as with "cosmos" 'thomocha' (), hybrids may be less scented than the species.