Subdivision below the rank of genus and above the rank of species.
A group of plants raised from seed and thus not genetically identical but sufficiently alike to be treated as a garden variety, for example most cultivars of annuals and vegetables.
A group of plants developed by a plant breeder and raised from seed and thus not genetically identical but sufficiently alike to be treated as a garden variety. A series may include several named cultivars, usually with the series name incorporated in their names. Most modern annual and vegetable seed is sold under a series name, though a true-breeding line of seedlings can be treated as a single cultivar.