Coined L.H. Bailey 1918
- a UK /ˈkʌltɪdʒɛn/|/ˈkʌltɪdʒən/
- Bailey, L.H. 1918. The indigen and cultigen. Science ser. 2, 47:306-308
- Spencer, R.D. and Cross, R.G. 2007. The cultigen. Taxon 56(3):938-940
A cultigen is a plant that has been deliberately altered or selected by humans; it is therefore the result of artificial selection not natural selection. These "man-made" or anthropogenic plants are, for the most part, the plants of commerce, those used in horticulture, agriculture and forestry. By far the greatest number of cultigens have been given cultivar names and a few givenGroup (formerly cultivar-group) names, with or without cultivar epithets. Cultigens include: selections of variants from the wild or cultivation including vegetative sports (aberrant growth that can be reproduced reliably in cultivation); plants that are the result of plant breeding and selection programs; genetically modified plants (plants modified by the deliberate implantation of genetic material); graft-chimaeras (plants grafted to produce mixed tissue, the graft material possibly from wild plants, special selections, or hybrids). The full range of plants that are given cultivar or Group names are detailed in the International Code of Nomenclature for Cultivated Plants (ICNCP). A few cultigens have not been given cultivar or Group names and these include: unnamed plants that are the result of breeding, selection, and tissue grafting; ancient cultigens - plants with binomials (i.e. without cultivar names) that occur in the wild but which have undergone selection and distribution by humans for so long that their original ancestral distributions and forms in the wild are uncertain or unknown; unnamed (presumed) anthropogenic plants no longer known in the wild.
Many ancient cultigens, like maize, Zea mays and banana, Musa x cavendishii, are precursors of important economic crops .
All plants in the above groupings remain cultigens when they are growing in the wild, whether they are naturalised or deliberately planted.
Formal definitionA cultigen is a plant whose origin or selection is primarily due to intentional human activity.
Origin of term
The word cultigen was coined in 1918 by American Liberty Hyde Bailey (1858-1954) an American horticulturist, botanist and cofounder of the American Society for Horticultural Science. He was aware of the need for special categories for those cultivated plants that had arisen by intentional human activity and which would not fit neatly into the Linnaean hierarchical classification of ranks used by the International Code of Botanical Nomenclature (ICBN). In his 1918 paper Bailey noted that for anyone preparing a descriptive account of the cultivated plants of a country (he was at that time preparing such an account for North America) it would be clear that there are two kinds of plants. Firstly, those that are of known origin or nativity "of known habitat". These he referred to as indigens. The other kind was: " ... a domesticated group of which the origin may be unknown or indefinite, which has such characters as to separate it from known indigens, and which is probably not represented by any type specimen or exact description, having therefore no clear taxonomic beginning." He called this second kind of plant a cultigen.
In 1923 Bailey extended his original discussion emphasising that he was dealing with plants at the rank of species and he referred to indigens as: " those that are discovered in the wild " and cultigens as plants that: " arise in some way under the hand of man " He then defined a cultigen as: "... a species, or its equivalent, that has appeared under domestication ..."
Bailey soon altered his 1923 definition of cultigen when, in 1924, he gave a new definition in the Glossary of his Manual of Cultivated Plants as: " Plant or group known only in cultivation; presumably originating under domestication; contrast with indigen " This, in essence, is the definition given at the head of this piece. This definition of the cultigen permits the inclusion of cultivars, unlike the 1923 definition which restricts the idea of the cultigen to plants at the rank of species. In later publications of the Liberty Hyde Bailey Hortorium, Cornell, the idea of the cultigen having the rank of species returned (e.g. Hortus Second in 1941 and Hortus Third in 1976) . Both cited publications indicate that the term cultigen is not synonymous with cultivar. "A cultigen is a plant or group of apparent specific rank, known only in cultivation, with no determined nativity, presumably having originated, in the form in which w know it, under domestication. Compare indigen. Examples are Cucurbita maxima, Phaseolus vulgaris, Zea mays''''". Subsequent usage in horticulture has maintained a distinction between cultigen and cultivar while allowing the inclusion of cultivars within the definition (see below).
Cultigens and cultivarsCultigen and cultivar may be confused with one-another. Cultigen is a general-purpose term encompassing not only plants with cultivar names but others as well (see introductory text above), while cultivar is a formal taxonomic (classification) category.
Although in his 1923 paper Bailey used only the rank of species for the cultigen, it was clear to him that many domesticated plants were more like botanical varieties than species and so he established a new classification category for these, the cultivar, generally assumed to be a contraction of the words “cultivated” and “variety”. Bailey was never explicit about the etymology of the word cultivar and it has been suggested that it is a contraction of the words “cultigen” and “variety” which seems more appropriate . He defined cultivar in his 1923 paper as: ... " a race subordinate to species, that has originated and persisted under cultivation; it is not necessarily, however, referable to a recognised botanical species. It is essentially the equivalent of the botanical variety except in respect to its origin ".
This definition and understanding of cultivar has changed over time (see current definition in cultivar).
Usage in botanyIn botanical literature the word cultigen is used for plants that have been given binomials and are now known only in cultivation (as plants of unknown origin, generally presumed to be human selections) but there is no essential difference in principle between these ancient plants and modern plants altered by human activity that are named under the International Code of Nomenclature for Cultivated Plants (ICNCP). The use of a Latin binomial (only) for such plants seems misleading (even though it is permissible under the ICBN) because binomials are overwhelmingly used for “wild” plants, and cultivar names used for virtually all cultigens.
The use of cultigen in this botanical sense essentially follows Bailey's definition of cultigen given in 1923.
Usage in horticultureIn horticulture the definition and use of the term cultigen has varied but generally, unlike usage in botany, it encompasses cultivars. One example is the definition given in the Botanical Glossary of The New Royal Horticultural Society Dictionary of Gardening which defines cultigen as: " A plant found only in cultivation or in the wild having escaped from cultivation; included here are many hybrids and cultivars, "...
The use of cultigen in this sense is essentially the same as the definition of the cultigen published by Bailey in 1924.
Other usageThe term cultigen is occasionally applied in a very general sense to any organisms that do not have a wild or uncultivated counterpart, see for example . Animal breeds raised in captivity would be included here. It might seem that the word "domesticate" could serve the same purpose as cultigen. However, the widely held view that domesticated plants and animals are simply wild plants and animals used in domestic situations (often as tamed wild animals, or plants introduced directly from the wild, rather than being specially selected for particular desirable characteristics) would not support this view. However there is debate about what constitutes domestication and some authors maintain that to be termed domesticated or a "domesticate" a plant or animal must have been "changed" in some way from its wild counterparts. Regardless of this debate, it is clear that the term cultigen originated within horticulture and botany and that these areas are where it has mostly been applied.
Recommended usageWider use of the term cultigen as defined here has been proposed for the following reasons:
- supports current usage in horticulture
- assists clarity in non-technical discussions about “wild” and “cultivated” plants (for example, cultivated plants as commonly understood (plants in cultivation) are not the same as the "cultivated plants" of the ICNCP, and the distinction between "wild" and "cultivated" habitats is becoming progressively blurred)
- has the potential to simplify the language and definitions used in the Articles and Recommendations of the ICNCP]
- gives greater precision and clarity to the definition of the respective scope, terminology and concepts of the International Code of Botanical Nomenclature (ICBN) and the International Code of Nomenclature for Cultivated Plants (ICNCP)
- avoids the potential for confusion within the ICNCP over its
scope, that is, whether it is concerned with:
- where plants are growing (in the wild or in cultivation)
- how they originated (whether they are the result of intentional human activity or not)
- simply providing a mechanism for regulating the names of those cultigens requiring special classification categories outside the Linnaean hierarchy of the ICBN i.e. cultivar and Group names .
Critique of definitionPotential misunderstandings and questions arising from the definition of cultigen given here have been discussed in the literature and are summarised below.
- What exactly does altered mean?
In cases like this the definition refers to "deliberate" selection and this would be of particular plant characteristics that are not exhibited by a plant's wild counterparts (but see Selections from the wild).
- What exactly does deliberately selected mean?
- What about plants selected from the wild?
- What about gene flow between populations?
Whether a plant is a cultigen or not does not depend on where it is growing. If it complies with the definition then it is a cultigen. Cases like this have always been difficult for botanical nomenclature. Unnamed progeny in the wild might be given a name like Lantana aff. camara (aff. = having affinities with) or may remain unnamed. Its cultigenic origin may or may not be recognised by the allocation of a cultivar name.
- Plants of unknown origin
- Difficult cases
If the cross in cultivation is followed by deliberate selection and naming then this will indicate a cultigen. However in a case like this it may not be possible to tell.
Etymology: culti(vated) or culti(cultigen) + gen (gens Latin - kind)
Further readingSpencer, R.D. and Cross, R.G. 2007. The cultigen. Taxon 56(3):938-940
Spencer, R, Cross, R & Lumley, P. 2007. (3rd edn) Plant names: a guide to botanical nomenclature. CSIRO Publishing, Collingwood, Australia. (Also CABI International Wallingford, UK.) The definition of cultigen given in the Glossary of this reference does not include deliberately selected plants that are identical to plants growing (or once growing) in the wild. ISBN 9780643094406 (pbk.).
- [http://126.96.36.199/cgi-bin/omd?query=cultigen] A definition of cultigen that includes organisms other than plants
- http://www.ishs.org/icra/index.htm International Society for Horticultural Science (includes links to ICBN, ICNCP, International Cultivar Registration Authorities).
cultigen in Russian: Культиген
cultigen in Ukrainian: Культиген