Most `` Vitis '' species have 38 chromosomes ( n = 19 ) , but 40 ( n = 20 ) in subgenus `` Muscadinia '' , while `` Ampelocissus '' , `` Parthenocissus '' , and `` Ampelopsis '' also have 40 chromosomes ( n = 20 ) and `` Cissus '' has 24 chromosomes ( n = 12 ) .
Most Vitis species have 38 chromosomes ( n = 19 ) , but 40 ( n = 20 ) in subgenus Muscadinia , while Ampelocissus , Parthenocissus , and Ampelopsis also have 40 chromosomes ( n = 20 ) and Cissus has 24 chromosomes ( n = 12 ) .