Variety, cultivar, landrace, heirloom: Definitions

I am often asked what is the difference between a variety, a cultivar, a landrace or an heirloom. I can see in various forum or websites a lot of opinions and some laudable efforts to explain with precision the definition of these terms. However, it is rarely accurate.

I try here to give not an opinion but precise and sourced definitions.

Short version

The analysis of the official definitions show that a Cultivar and a Variety have exactly the same meaning. Both shall be i) describable and described, ii) Distinct and iii) stable after propagation. As additional criteria for a Variety eligible for Breeder’s right, it shall be new (not previously commercialized) and different from any variety of common knowledge. A Landrace is a locally adapted variety that is not bound to be stable after propagation as the one advantageous property of a Landrace is that its genetic composition may change over time, under either aware or unaware human selection,  to optimally fit its environment and the local farming system. Hence, while a landrace is describable and described, is distinct, it is not necessarily stable after propagation. Hence, a Landrace is different from a cultivar = a variety because it can be a dynamic, changing group of plants. Heirloom can be equated to Landrace.
Synthetic definition of Cultivar, Variety, Registrable Variety and Landrace
Synthetic definition of Cultivar, Variety, Registrable Variety and Landrace

In coffee:

Examples of Cultivar = varieties: Bourbon, Typica, Obata, Catigua, Geisha, SL-28, Marsellesa Examples of varieties that are not eligible for Breeder’s rights = Bourbon, Typica, SL-28…because they are of ancient common knowledge Example of Landraces =
  • Most cultivated Robusta coffee (canephora) in Africa.
  • Most cultivated Arabica coffee in Ethiopian, apart from varieties selected by research, in South Sudan and in Yemen.
  • Outside of Ethiopia and Yemen, I would argue that the Timor Hybrid population in East Timor is forming a landrace.

In details

Let’s start with cultivars and varieties. The acknowledged official sources for the definition of what is a variety and what is a cultivar are the “International Code of Nomenclature for Cultivated Plants” (ICNCP) and the “International Convention for the Protection of New Varieties of Plants” (ICPNVP), respectively.

ICNCP (Cultivar) is produced by the “International Society for Horticultural Science” (ISH) whereas ICPNVP (Variety) is produced by the “International Union for the Protection of New Varieties of Plants” (UPOV).

INCP (Cultivar) is born as a specific code of nomenclature for cultivated plants derived in the 50’s from the “International code of Botanical Nomenclature” that has now become the “International Code of Nomenclature for algae, fungi and plants” produced by the “International Association for Plant Taxonomy” (IAPT).

Interestingly, in the glossary of the “International Code of Nomenclature for algae, fungi and plants”, there is no definition of “variety” while the definition of Cultivar is present and points to the International Code of Nomenclature for Cultivated Plants”.

UPOV’s mission statement is “to provide and promote an effective system of Plant Variety Protection, with the aim of encouraging the development of new varieties of plants, for the benefit of the society”

Hence, the roots of the definition of a cultivar and a variety are to be found in the science of Botany/Taxonomy and Breeding/Genetics/, respectively.

Let’s have a look to the various definitions.

Definition of a Cultivar (ICNCP/ISH)

The definition of a Cultivar is given in Article 2.3.

“A cultivar is an assemblage of plants that (a) has been selected for a particular character or combination of characters, (b) is distinct, uniform, and stable in these characters, and (c) when propagated by appropriate means, retains those characters”

Definition of a variety (ICPNVP / UPOV)

Article 1 (vi) of the 1991 Act of the UPOV Convention is reproduced below:

“Variety” means a plant grouping within a single botanical taxon of the lowest known rank, which grouping, irrespective of whether the conditions for the grant of a breeder’s right are fully met, can be:

  • Defined by the expression of the characteristics resulting from a given genotype of combination of genotypes
  • Distinguished from any other plant grouping by the expression of at leas one of said characteristics and
  • Considered as a unit with regard to its suitability for being propagated unchanged

Definition of a variety that can be granted a Breeder’s right (ICPNVP / UPOV)

Article 5 states that the criteria to be satisfied for a Breeder’s right to be granted for a given variety are: New, Distinct, Uniform and Stable.

Hence, for UPOV, the difference between a variety and a variety eligible to a breeder’s right is that the later should be new.

New, as per UPOV definition (Article 6), means that the variety should not have been commercialized at the time of applying for a breeder’s right.

UPOV also recognized that the New variety shall be “clearly distinct from any other variety whose existence is a matter of common knowledge at the time of the filing of the application”

For instance, the coffee variety “Bourbon” is a variety as per the UPOV definition but it is not eligible to breeder’s right because its existence is a matter of common knowledge.

Definition of a Landrace

There is no official acknowledge definition of a Landrace.  However, the concept has been discussed at length, namely by Zeven in 1998, and Casañas et al in 2017. We find that the easiest, yet valid, definition is given by Casañas et al in 2017 in their abstract:

“The term “landrace” has generally been defined as a cultivated, genetically heterogeneous variety that has evolved in a certain ecogeographical area and is therefore adapted to the edaphic and climatic conditions and to its traditional management and uses. Despite being considered by many to be inalterable, landraces have been and are in a constant state of evolution as a result of natural and artificial selection”.

Definition of Heirloom

The etymology of Heirloom is a “tool” that is inherited (“heir”) from ancestors. There is no major differences between heirloom and landraces.

Note on Varietals:

“Varietal” is a word coming from the wine industry refereeing to the wine coming from one single variety. It is sometimes used in the coffee industry but unfortunately often using varietal as a synonymous of variety: which is not correct.

Note on the concept of accession

You might have heard or read the term “Accession”. Let’s read the definition by the US National Plant Germplasm System : “An accession is a distinct, uniquely identified sample of seeds or plants, that is maintained as part of a germplasm collection.”

An accession is hence relate to germplasm (= genetic resources) collection. It can represent a variety, a sample of a landrace or a sample of wild populations.

Coffee germplasm collection are crucial for the preservation of coffee biodiversity.

Note on genetic groups

In the “International Code of Nomenclature for algae, fungi and plants”, various terms might describe the different taxonomic groups within a species. Some groups of plants within a species are genetically distinct without forming “varieties”. In most common coffee species, genetic groups have been described: namely in C. canephora (Montagnon et al, 2012; Garavito et al, 2016), in C. arabica (Montagnon et al, 2022) and C. liberica (N’diaye et al, 2005). These genetic groups might represent mother populations of important varieties (Montagnon et al, 2022).