brassica oleracea broccoflower broccoli broccoli-cauliflower cross cauliflower cauliflower cultivar cross-pollination cruciferous cultivar curd color curd colour edible flavor flavour food green green cauliflower green-headed inflorescence inflorescence meristems milder nutritious plants sweeter texture vegetable vegetables white cauliflower brassica-oleracea broccoli-cauliflower-cross cauliflower-cultivar fresh green-cauliflower inflorescence-meristems mild raw sweet uncooked white-cauliflower