agricultural science artificial selection asexual reproduction botanical name cabbage canola cauliflower cloning cultigen cultivar group english language epithet forestry genetic engineering genome grafting granny smith horticulture hosta international code of nomenclature for cultivated plants international cultivar registration authority international society for horticultural science japanese language latin leucospermum liberty hyde bailey osteospermum patent plant plant breeding plant propagation pseudonym red delicious royal horticultural society species tasmania taxon trademark