World Checklist of Selected Plant Families (WCSP)

About the Checklist


In 1994 Rafaël Govaerts was employed by the Royal Botanic Gardens, Kew to compile a checklist of the genus Quercus. This quickly grew to a checklist of the whole of the Fagales. He had also been compiling the World Checklist of Seed Plants since 1988 and the fist volume of this work was published in 1995. Because of its usefulness, a programme was initiated to compile global checklists of plant families of particular interest and expertise to Kew. The families selected were mainly those that were a research focus for Kew, for which a Generic account had been published or for which expert staff was about to retire. From 2001 as the programme grew and more contributors and institutions became involved, the focus became concentrated on compiling all Monocotyledon families, which was completed in 2006. The programme then focused on contributing to a working list of known Seed Plants as set out by the Convention for Biological Diversity (CBD) as their Target 1. As the programme became more widely known and the publications more widely used, external interest increased to contribute. Many more experts helped to review the data and from 2002 a number of externally compiled checklists were supported and incorporated in the data set. This process is ongoing and further contributions facilitated. The main goal of the checklists is to provide high quality peer reviewed baseline data on all accepted taxa included in each family. The main focus being the name as this is the single most important element necessary to communicate about plants and the key to biodiversity information. The main focus of the checklist is to provide the state of current knowledge on a family rather than revising a family, a task that is being undertaken by the Species Plantarum programme. Included is also associated data like author, place of publication, full synonymy, geographical distribution and life form. The two main research elements are the name and the distribution, both of which can be used to create individually tailored checklists. As technology progressed, more options became possible and from 2005, references were attached to each name, indicating different taxonomic opinions. Also one reference is linked to each of the TDWG geographical codes to substantiate the presence in that area. This is quite a unique option and would be very hard to achieve in a paper copy.

WCSP has now become an international collaborative programme with more than 150 contributors from 22 countries. As more families are compiled and made available online, the more this number grows. There has also been a considerable amount of data sharing with researchers and other online data providers who have incorporated large numbers of WCSP records.

The database is live and updated daily. Newly published names however are automatically added from IPNI to the database but are only made visible on the website after an editing phase of about one year. So remember that if you publish a name in November 2015, it will probably be entered into IPNI in the beginning of 2016 and may take until 2017 before it becomes visible on the website.

Rafaël Govaerts


This checklist is derived from a database complying with the data standards proposed by the Taxonomic Databases Working Group (TDWG). The data set was initially stored in Foxbase and then in 2000 transferred to an Access database. During March 2004 the data set was transferred again and is now stored in Sybase.


All names strictly follow the rules of the International code of nomenclature (ICN). The orthography follows the rules as prescribed by the ICN. As the ICN follows the type method, the synonymy is based on the type of the name only, which may differ from the literature or common usage.

The database is live and updated daily. Newly published names however are automatically added from IPNI to the database but are only made visible on the website after an editing phase of about one year. So remember that if you publish a name in November 2015, it will probably be entered into IPNI in the beginning of 2016 and may take until 2017 before it becomes visible on the website.

Generic concepts follow an evolutionary classification wherever the names are available and is primarily based on the Vascular Plant Families and Genera. Wherever more recent global generic lists have been published they have been followed. In particular for Orchidaceae the generic concepts of the recent publication Genera Orchidacearum is followed wherever the species names exist.

Place and date of publication of all names are given. Citation of authors follows Authors of Plant Names; for book abbreviations, the standard is Taxonomic Literature, 2nd edn, or TL/2 for short (Stafleu & Cowan 1976-88; supplements, 1992-2000); and periodicals are abbreviated according to BPH-2 (Bridson, 2004). A question mark (?) following a name and author indicates that a place of publication has yet to be established. Names of nothospecies ('hybrids') are preceded by a multiplication sign (*), with the place of publication being followed by the names of the parents if known. Basionyms or replaced synonyms of accepted names are designated by an asterisk (*).

Acceptance of species and infraspecific taxa is based not only on assessments of literature and common practice but also, where possible, by reference to specialist advice and (where necessary) to the herbarium or living collections. The general rule is that the latest published species taxonomy and synonymy is followed within the accepted generic concepts. The checklist preferred view may however differ if experts advise otherwise, if it is clear the latest publication was not aware of the previous taxonomy (as it is e.g. not included in the bibliography) or a more global authoritative publication is followed rather than a partial local one. Different taxonomies are expressed (from 2005) in the references cited. A preferred view is however given as in most cases there is no difference of opinion (at species level) and where there is (in our experience less than 1 %) most users still prefer one unambiguous answer, which will be the one of the main reviewer. For those specialists interested in the different opinions, the data is there as well.

The References express the published or communicated data only. This means that many homotypic and other synonyms do not have any references as an author may only publish A is a synonym of B and not list all the homotypic synonyms of A. From this statement however, it can be logically concluded that all homotypic names based on A are synonyms of B. Similarly an author may publish that A is a synonym of B and another author that B is a synonym of C. The database will then logically show that A is a synonym of C even though no author may ever have explicitly published this. Heterotypic synonyms without references may often have received this data from the original name data, which is mostly Index Kewensis vol. 1-2. For accepted taxa, the protologue is of course also a reference in which the name is accepted. For non-accepted references, the name under which it was synonymised is listed in square brackets. Names may be synonymised implicitly. If a name is not included in a revision of the group or geographical area to which it belongs, we implicitly conclude that the name is not accepted. Infraspecific taxa are then normally synonymised with their higher taxon. Species are listed as unplaced.

If there is disagreement on the infraspecific rank at which a name should be accepted, the following key is used following Brummitt (1990) and Wood. & al. (2015):

1 Distribution range separate (so that non-overlapping rings can be drawn round them on a map) or nearly so, gene flow absent or very restricted between the infraspecific populations and differing in characters that are significant for taxonomic species differentiation within the

1 Distribution ranges overlapping, gene flow possible and not differing in characters that are significant for taxonomic species differentiation within the genus........................................2.

2 Populations separate........................................var.

2 Mixed populations present........................................f.

Species numbers

The number of known species accepted in the checklist are available for all families and genera included in WCSP. For the family species numbers go to the list of Families included. For the numbers within genera use the "Build a checklist" option and select the required family and genus name and click on "create a checklist" at the bottom of the page. The species number of each genus is then listed below the genus entry. The numbers generated are species numbers only, excluding hybrid and infraspecific taxa. If you use the geographical option as well in the report builder, beware that introduced species are counted as well. If you use these numbers, please don't forget to cite us with the appropriate date on which you did the count as this may change over time.


From 2005 references have been added. They can be viewed under the tabs "Accepted by" which lists references that accept the name and "not accepted by" which list references that do not accept the name. At the end of those references, in square brackets, the accepted name used in that publication is listed if it is synonymised. As WCSP has a very diverse user group, both highly scientific botanical as well as mainstream horticultural publications are listed to reflect the broad use age of the name.

Geographical Distribution

Distributions of species and taxa of lower rank are furnished in two ways: firstly by a generalised statement in narrative form, and secondly as TDWG geographical codes (Brummitt, 2001) expressed to that system's third level. Examples of the former include:

  • Texas to C. America
  • Mexico (Veracruz)
  • Europe to Iran
  • E. Himalaya, Tibet, China (W. Yunnan)
  • Philippines (Luzon)
  • S. Trop. America

When the presence of a taxon in a given region or location is not certainly known, a question mark is used, e.g. New Ireland ?; when an exact location within a country is not known, a question mark within brackets is used, e.g. Mexico (?). Distributions of genera are furnished in a relatively simplified form, any special features being given within brackets.

With respect to the TDWG codes, the region is indicated by the two-digit number (representative of the first two levels), the first digit also indicating the continent. The letter codes following the digits, when given, represent the third-level unit (a country, state or other comparable area). They usually are the first three letters of a given unit's name, but sometimes are contractions. When pointing to a particular code, the complete name will be provided. If the country code is not known, '+' is used. For taxa that are known or appear to be extinct in a given region, '†' is used after the country code. Naturalisation is expressed by putting the third-level codes in lower case and, if in a second-level region all occurrences are the result of naturalisation, the code number for the region is placed in brackets. The application of question marks is as indicated above for geographical regions. Examples include:

  • 12 SPA [SW. Europe: Spain]
  • 32 + [C. Asia (more exact distribution not known)]
  • 36 CHN? 38 JAP KOR [Doubtful in China North Central, Eastern Asia; Japan and Korea]
  • 51 NZN NZS [New Zealand: North and South Islands]
  • (76) ari 77 NWM TEX [SC. U.S.A., naturalized in Arizona]
  • 77 TEX† [SC. U.S.A.: Texas, where extinct]

The complete list of TDWG codes can be downloaded from
Most of the geographical terms used can be found in the Times Atlas 2000.


The terminology for life-forms, definitions of which follow, is based on the system of Raunki?r (1934, especially chapters 1 and 2) with modifications derived from Flora van Belgi?, het Groothertogdom Luxemburg, Noord-Frankrijk en de aangrenzende gebieden (De Langhe et al. 1983: pp. xvii-xviii, 869 (fig. 16)). Many plant families have their own particular lifeforms. It is therefore only attempted to give a very broad and general lifeform, mainly to aid global searches over different groups.

Main Categories:

phanerophyte (phan.)
stems: woody and persisting for several years
buds: normally above 3 m
e.g.: small and large trees

herbaceous phanerophyte (herb. phan.)
stems: herbaceous and persisting for several years
buds: above soil-level
e.g.: Musa balbisiana

nanophanerophyte (nanophan.)
stems: woody and persisting for several years
buds: above soil level but normally below 3 m
e.g.: shrubs

chamaephyte (cham.)
stems: herbaceous and/or woody and persisting for several years
buds: on or just above soil level, never above 50 cm
e.g.: Alyssum, Acaena, Acantholimon, Saxifraga

hemicryptophyte (hemicr.)
stems: herbaceous, often dying back after the growing season, with shoots
at soil level surviving
buds: just on or below soil level
e.g.: Aster, Viola odorata

hemicryptophytes that survive unfavourable seasons in the form of a rhizome, bulb, tuber or rootbud.
The term tuber is used here in a broad sense and includes every storage organ that is not a rhizome, bulb or rootbud.

helophyte (hel.)
hemicryptophytes that grow in soil saturated with water or in water. leaf and flower
bearing shoots rise above water
e.g.: Typha, Echinodorus

stems: vegetative shoots sunk in water
buds: permanently or temporarily on the bottom of the water

hydrohemicryptophyte (hydrohemicr.)
e.g. Stratioides

e.g. Nymphaea, Nuphar

hydrotherophyte (hydrother.)
e.g. Lemna, Utricularia vulgaris

therophyte (ther.)
plants that survive unfavourable seasons in the form of seeds and complete their life-history during the favorable season.
e.g. annuals



Additional information

climbing (cl.)
e.g.: cl. phan.: Hedera helix
cl. nanophan.: Clematis florida
cl. hemicr.: Vicia cracca
cl. tuber geophyte: Tropaeolum tuberosum
cl. ther.: Pisum sativum
(cl.) nanophan: for plants that are sometimes climbing
succulent (succ.)
e.g.: succ. nanophan.: Opuntia ficus-indica
succ. cham.: Lophophora williamsii
succ. ther.: Sedum azureum
cl. succ. nanophan.: Cissus quadrangula

Epiphytic and lithophytic
Growing on trees or rocks, without extracting nutrition from the host.

parasitic (par.)
hemiparasitic (hemipar.)
parasitic plants that are still able to photosynthesise
e.g. Viscum album is a hemipar. nanophan.
holoparasitic (holopar.)
parasitic plants that are fully dependent on their host
e.g. Orobanche ramosa is a holopar. ther.

holomycotroph (often wrongly called saprophyte)
e.g. Neottia nidus-avis is holomycotroph.

Abbreviations used

al.alii: others
app.approaching, close to
auct.of author
cit.citatus: cited
comb.combinatio: combination
cons.conservandus: to be conserved
cppo.centre page pull-out
cult.cultus: cultivated
cv.cultivarietas: cultivar
DT. dry tropical (desert/steppe)
E.East(ern) cetera: and the rest
e.g.exempli gratia: for example
hort.hortorum: of gardens
ICBNInternational Code of Botanical Nomenclature est: that is
ign.ignotus: unknown
in litteris: in correspondence
ined.ineditus: unpublished and not validated, provisional name
inq.inquilinus: naturalised
i.q.idem quod: the same as
Kep.kepulauan (islands)
Khr. Khrebet: mountain range
MTmonsoon tropical (savanna)
n.?numero: number orchid hybrids
nom. alt.nomen alternativum: alternative name
nom. cons.nomen conservandum: name conserved in ICBN
nom. illeg.nomen illegitimum: illegitimate name
nom. inval.invalid name
nom. nud.nomen nudum: name without a description
nom. provis.nomen provisorium: provisional name
nom. rej.nomen rejiciendum: name rejected in ICBN
nom. superfl.nomen superfluum: name superfluous when published
nov.novus: new
opus utique oppr.opus utique oppressa: suppressed publication in ICBN
orth. var.orthographic variant
phan.phanerophyte parte: partly
pro synonymum: published as a synonym
q.e.quod est: which is
q.v.quod vide: which see
seq.sequens: following
s.l.sensu lato: in the broad sense
s.p.sine pagina:without page number
sphalm.sphalmate: by mistake
s.s.sensu stricto: in the narrow sense
syn.synonymon: synonym
vol.volume: volume
viz.videlicet: namely
WTwet tropical
?not known, doubtful
+distribution incomplete
*basionym/replaced synonym


Bridson, G., comp. & ed. (2004). Botanico-Periodicum-Huntianum/Second Edition. Pittsburgh: Hunt Institute for Botanical Documentation.
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Brummitt, R. K. & Powell, C. E., (1992). Authors of Plant Names. 732 pp. Kew: Royal Botanic Gardens. []
De Langhe, J. E. et al. (1983). Flora van Belgi?, het Groothertogdom Luxemburg, Noord-Frankrijk en de aangrenzende gebieden. civ, 970 pp., illus., map. Patrimonium, Nationale Plantentuin van Belgi?, Meise.
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Farr, E. R., Leussink, J. A. & Zijlstra, G. (eds). (1986). Index Nominum Genericorum (Plantarum): Supplementum I. xv, 126 pp. Bohn, Scheltema & Holkema, The Hague. (Regnum Vegetabile, 113.)
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Greuter, W. et al. (1993). Names in Current Use for Extant Plant Genera (Names in current use, 3). xxvii, 1464 pp. Koeltz, Koenigstein. (Regnum Vegetabile.)
Raunki?r, C. (1934). The Life Forms of Plants and Statistical Plant Geography. xvi, 632 pp., illus. Oxford University Press, London.
Stafleu, F. & Cowan, R. S. (1976-88). Taxonomic Literature: A Selective Guide to Botanical Publications and Collections with Dates, Commentaries and Types. 2nd edn. 7 vols. Utrecht: Bohn, Scheltema & Holkema. (Regnum Vegetabilie 94, 98, 105, 110, 112, 115, 116.) Continued as Stafleu, F. et al.. (1992-2000). Taxonomic Literature, Supplement. Vols. 1-6. Koenigstein, Germany: Koeltz. (Regnum Vegetabile 125, passim. As of 2000 six volumes published.)[]

Wood, J.R.I., Williams, B.R.M., Mitchell, T.C., Carine, M.A., Harris, D.J. & Scotland, R.W. (2015). A foundation monograph of Convolvulus (Convolvulaceae). PhytoKeys 51: 19.