What is a cultivar?

A cultivar, as a taxon, is an assemblage of plants that

  1. has been selected for a particular characteristic or combination of characteristics, and

  2. remains distinct, uniform, and stable in these characters when propagated by appropriate means

Let's break that down:

  • Taxon – A taxonomic group of organisms that form a unit

  • Assemblage of plants – A group of plants, not a single specimen

  • Particular character or combination of characters – Morphological characters like leaf blade shape or color, growth habit, floral characteristics etc. either individually or a combination of them

  • Remains distinct – The distinguishing characteristics are retained as the plants are propagated and grown

  • Uniform – Distinguishing characteristics are observable and within reason constant across all the plants of the cultivar

  • Stable – Distinguishing characteristics are persistent

  • Propagated by appropriate means – Usual mechanisms to create clones like through asexual reproduction  (cuttings, air-layering, tissue culture) or by seed where seedlings come ‘true’ to the parent cultivar

Accepted origins of a cultivar

  1. A selected and propagated wild individual (via stem cuttings, tubercles, leaves etc), usually possessing some quality that differentiates it from the “norm” of its species

  2. A selected and propagated seedling pertaining to a species in the wild, usually possessing some quality that differentiates it from the “norm” of its species

  3. A selected and propagated seedling from any deliberate or accidental cross within or between species and hybrids

  4. Selected [or all] seedlings from a cultivar which produces seed asexually

  5. A selected and propagated sport shoot (i.e. a shoot that is different from the main plant, e.g. variegated)

  6. A selected and propagated variant arising from tissue culture

  7. A selected and propagated plant which is the product of changed ploidy (chromosome number); e.g. a tetraploid

  8. A selected and propagated plant resulting from deliberate genetic modification

  • Note: Other kinds of cultivar exist in plants generally, but we are not aware that they arise in aroids. A full list can be found in the International Code of Nomenclature for Cultivated Plants.

Unaccepted origins of a cultivar

  1. In considering whether two or more plants belong to the same or different cultivars, their origins are irrelevant. Plants that cannot be distinguished from others by any of the means currently adopted for Araceae cultivar determination are treated as one cultivar.

  2. Plants whose characteristics are maintained solely by regular practices of cultivation are not to be considered as distinct cultivars. Note that variegated plants which may require long term maintenance by the removal of non-variegated shoots can be considered cultivars.

    However, plants that need regular chemical treatment to maintain its characteristics, like the Philodendron PINK CONGO, will not be considered cultivars.

Next recommended reading: Hybrid Araceae Cultivars

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