Guidelines for Araceae Hybrids

  1. Hybrids are plants created by intentional or unintentional pollination of two different plants. It could be between species, forms or cultivars (including hybrids). In some cases it can even be between different genera though this is relatively rare in Araceae. 

  2. The most desirable seedling is identified from the seedlings of a crossing. This seedling should be propagated asexually to form an assemblage of clones to confirm that the desired characteristics are consistent, stable and distinct from other known cultivars and species. Then it be designated a cultivar name for registration.

    • Note that different seedlings from this crossing can be designated different cultivar names if they are distinct enough and consistent when cloned. 

  3. If a similar plant was created/identified elsewhere it will continue to carry the same cultivar name if it is indistinguishable from the established cultivar

    • There could have been multiple instances of Philodendron bipinnatifidum × P. speciosum being created  in cultivation but if the progeny look indistinguishable then they will carry the same name as the original cross, Philodendron ‘Evansii’

Exception – Nothospecies

  1. Nothospecies – a botanical designation for plants thought to be natural hybrids of two species

  2. All crosses of these two species or crosses between any of the progeny and one of the parents (backcrossing) will carry the same name despite how variable they are

    • Example: Philodendron × lucasiorum – a natural hybrid of Philodendron melinonii and P. linnaei

  3. Worth noting that cultivars of nothospecies can be established if distinct plants are identified and a group is made via asexual reproduction (cloning).

    • Example: A cultivar of Philodendron × lucasiorum could be established like Philodendron × lucasiorum ‘Paddle Leaf’ (fictional)

Concept of Grex

  1. Grex is the idea of grouping plants only based on parentage. Parents can be species or another grex. It applies to the reverse (reciprocal) cross as well.

  2. This would mean that all seedlings of a particular cross will carry the same name irrespective of the clones used in that cross.

    • Species A × Species B = Grex X

    • Species B × Species A = Grex X

  3. Grex X will apply to any cross of these two species but not to backcrosses

    • Grex X × Species A ≠ Grex X

    • Species B × Grex X ≠ Grex X

  4. Applies ONLY to Orchids. This CANNOT be applied to Araceae.

Refer to the International Code of Nomenclature for Cultivated Plants for full set of guidelines for naming and accepting cultivars: https://www.ishs.org/sites/default/files/static/ScriptaHorticulturae_18.pdf