Savoy cabbage ("Brassica oleracea" var. Napa cabbage might have originated from natural hybridization between turnip (Brassica rapa subsp. Broccoli is classified in the Italica cultivar group of the species "Brassica oleracea". Bok choy (American English), pak choi (British English), or pok choi ("Brassica rapa" subsp. "Brassica rapa" species are diploid and have 10 chromosomes. Rapeseed belongs to the genus "Brassica". Broccoli resembles cauliflower, which is a different cultivar group of the same "Brassica" species. "Raphanobrassica" includes all intergeneric hybrids between the genera "Raphanus" (radish) and "Brassica" (cabbages, etc.). "Se"-methylselenocysteine occur naturally in plants of the genera "Allium" and "Brassica". Clubroot is a soilborne disease caused by the biotrophic protist "Plasmodiophora brassica". The species "Brassica napus" belongs to the flowering plant family Brassicaceae. It occurs in seeds of Brassica and Crucifera species. This interspecific breeding allowed for the creation of three new species of tetraploid "Brassica". Many agriculturally important plants of the genus "Brassica" are also tetraploids. It is a self-compatible pollinating species like the other amphidiploid "brassica" species.