Seeds and sunflower plants derived from cultivar RW-B and having increased resistance to herbicides relative to wild-type plants are provided. These plants contain a new genetic mutation in the AHAS gene which confers broad spectrum resistance to a combination of an imidazolinone, a sulfonylurea, a triazolopyrimidine, and a pyrimidinyloxybenzoate herbicide and mixtures thereof, including (i) resistance to cloransulam-methyl present in a concentration of at least 67 grams of active ingredient per hectare; and (ii) resistance to the mix of imazapyr present in a concentration of at least 160 grams per hectare and metsulfuron present in a concentration of at least 10 grams per hectare. RW-B is true breeding for the morphological traits of producing a plant with a single head, a yield of greater than one tonne per hectare and for producing a seed having an oil content of greater than 40%.