The basic search of chromosome data of each taxon is done by the published names in the original sources. It can be carried out by genus, by species or infraspecific taxon (it is a drop-down autocomplete menu of ephitets if the genus is indicated beforehand. If is not indicated, a search by only the epithet can be made, but the drop-down autocomplete menu is not displayed), by the gametophytic number “n”, by the sporophytic number “2n”, by the year of publication, by the publication reference (in a drop-down autocomplete menu) or by any author or authors who have intervened in the publication. The search is hierarchical.

The result of each search is displayed in a summary page with all counts for the taxon, indicating the published name (standardized), the consensus name after revision, the country or geographic region, n, 2n, the bibliographic reference, and the link to the detailed page for each report found.

In the detailed page, information is structured by several blocks:

Systematics: it contains the scientific name published literally in the original document [“Published name (original)”], the name accepted following the usual standards [“Published name (standardized)”], the database name after revision [“Consensus name”], and comments on taxonomic or nomenclatural aspects [“Systematic notes”].

Chromosome count: it comprises the chromosome numbers as published [“n”] or [“2n”], the inferred ploidy level [“Ploidy”], and if the chromosome number or ploidy level is estimated by flow cytometry [“Estimated by flow cytometry”]. Presence of B-chromosomes is indicated in the same chromosome number.

Geographic data: it covers information on the country or region [“Country or region”], the location of the population [“Locality”], elevation in meters above sea level [“Elevation”], geographic coordinates [“Coordinates”] in standardized format (sexagesimal or centesimal) or UTM (Universal Transverse Mercator), and ecological data [“Ecological information”].

Karyology: it includes the type of material [“Material”] used, the existence of graphic information such as photographs [“Photo”], drawing plates [“Drawing”], karyograms [“Karyogram”] or idiograms [“Idiogram”], the original formula given by authors [“Formula (original)”], and the often interpreted haploid formula [“Formula (haploid)”], the measurements [“Chromosome measures”] and type [“Type of measurements”], the presence of satellites [“Satellites”], their number (in the haploid idiogram) [“N of satellitized pairs”], and their position [“Satellite position (pair + arm)”]. Also, the studies of banding [“C-Banding”], FISH (Fluorescence in Situ Hybridization) [“FISH”], measurements of the amount of DNA [“C-Values”], or the presence of B chromosomes [“B Chromosomes”]. Comments or observations on karyological aspects, if necessary, are also indicated [“Karyological notes”].

Specimen: it shows the voucher of the studied material, including the reference of the collector [“Ref. Collector”], the date of collection [“Date”], the name(s) of collector(s) [“Collector”], the reference of the voucher [“Voucher”], the acronym [“Herbarium (acronym)”] and the full name of the herbarium [“Herbarium (name)”] where the voucher has been deposited. If the taxon is identified as another one in the voucher, it is mentioned in “Systematic notes”.

Reference: it contains the full reference [“Complete reference”], and the corresponding DOI or another electronic address to access the document by the internet [“DOI and other links”]. If the same chromosome count has been reported elsewhere, the publication reference is indicated ["Count additional information"], which can be searched in the Basic search query.

The advanced search of chromosome data of each taxon is done by the names after revision and it is an exhaustive search, showing all the counts described under that name or synonym (following the criteria of Plants of the World Online - POWO or specialists), if comes out with different names in surveys where the count is cited or identified differently in the voucher. It can be carried out by genus, by species, by infraspecific taxon or by only the ephitet written in a single box (in this search, the name must be written in full and no drop-down autocomplete menu appears), by the gametophytic number “n”, by the sporophytic number “2n”, by the year of publication, by the publication reference (in a drop-down autocomplete menu) or by any author or authors who have intervened in the publication. The search is hierarchical.

The result of each search is displayed in a summary page with all counts for the taxon, indicating the published name (standardized), the consensus name after revision, the country or geographic region, n, 2n, the bibliographic reference, and the link to the detailed page for each report found.

In the detailed page, information is structured by several blocks:

Systematics: it contains the scientific name published literally in the original document [“Published name (original)”], the name accepted following the usual standards [“Published name (standardized)”], the database name after revision [“Consensus name”], and comments on taxonomic or nomenclatural aspects [“Systematic notes”].

Chromosome count: it comprises the chromosome numbers as published [“n”] or [“2n”], the inferred ploidy level [“Ploidy”], and if the chromosome number or ploidy level is estimated by flow cytometry [“Estimated by flow cytometry”]. Presence of B-chromosomes is indicated in the same chromosome number.

Geographic data: it covers information on the country or region [“Country or region”], the location of the population [“Locality”], elevation in meters above sea level [“Elevation”], geographic coordinates [“Coordinates”] in standardized format (sexagesimal or centesimal) or UTM (Universal Transverse Mercator), and ecological data [“Ecological information”].

Karyology: it includes the type of material [“Material”] used, the existence of graphic information such as photographs [“Photo”], drawing plates [“Drawing”], karyograms [“Karyogram”] or idiograms [“Idiogram”], the original formula given by authors [“Formula (original)”], and the often interpreted haploid formula [“Formula (haploid)”], the measurements [“Chromosome measures”] and type [“Type of measurements”], the presence of satellites [“Satellites”], their number (in the haploid idiogram) [“N of satellitized pairs”], and their position [“Satellite position (pair + arm)”]. Also, the studies of banding [“C-Banding”], FISH (Fluorescence in Situ Hybridization) [“FISH”], measurements of the amount of DNA [“C-Values”], or the presence of B chromosomes [“B Chromosomes”]. Comments or observations on karyological aspects, if necessary, are also indicated [“Karyological notes”].

Specimen: it shows the voucher of the studied material, including the reference of the collector [“Ref. Collector”], the date of collection [“Date”], the name(s) of collector(s) [“Collector”], the reference of the voucher [“Voucher”], the acronym [“Herbarium (acronym)”] and the full name of the herbarium [“Herbarium (name)”] where the voucher has been deposited. If the taxon is identified as another one in the voucher, it is mentioned in “Systematic notes”.

Reference: it contains the full reference [“Complete reference”], and the corresponding DOI or another electronic address to access the document by the internet [“DOI and other links”]. If the same chromosome count has been reported elsewhere, the publication reference is indicated ["Count additional information"], which can be searched in the Basic search query.