The International Nepenthes Grex Registry

Horticultural hybrids:

Naming priority is established by the date of pollination of a registered grex. However, because a grex is defined as the crossing of two genetically unique plants (not the crossing of two species), disputes over naming rights are rare.

Horticultural species and natural hybrids:

According to the rules of the INGR, horticultural species and natural hybrids retain their scientific names but are assigned a subsequent grex epithet by the breeder. In the case where a breeder makes multiple greges of the same combination, later greges are assigned a numerical suffix.

Example:

In November of 2002, the curator of the Vetter Botanical Gardens made a crossing of two distinct forms of N. maxima from diverse locations. Later this grex was registered as

N. maxima Vetter Gardens 2002-11

In August of 2004, this same breeder made another maxima crossing, using the exact same parent specimens, and the progeny were later registered as

N. maxima Vetter Gardens1 2004-8

In May of 2005, the owner of Blueridge Nursery crossed two other forms of N. maxima. These two plants, however, were not the same individuals used in the Vetter Gardens greges. A couple years later, the Blueridge cross was registered as

N. maxima Blueridge 2005-5