ChromoDB: chromosome counts database for vascular plants

Data Records

The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 213,427 records.

2 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versions

The table below shows only published versions of the resource that are publicly accessible.

How to cite

Researchers should cite this work as follows:

Simon J, Bosch M, Goncalves E, Blanché C (2026). ChromoDB: chromosome counts database for vascular plants. Version 2.3. Botany Section, Department of Biology, Health and Environment (University of Barcelona). Occurrence dataset. https://doi.org/10.15470/ninpvc

Rights

Researchers should respect the following rights statement:

The publisher and rights holder of this work is Botany Section, Department of Biology, Health and Environment (University of Barcelona). This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: 58dd7802-12e3-47c4-af69-90d440fc8305.  Botany Section, Department of Biology, Health and Environment (University of Barcelona) publishes this resource, and is itself registered in GBIF as a data publisher endorsed by GBIF Spain.

Keywords

Occurrence; chromosome numbers; chromosome counts; plant cytogenetics; karyology; polyploidy; vascular plants; data curation; literature-based data; taxonomy; bibliographic traceability; POWO; ChromoDB

Contacts

Geographic Coverage

Global. In this release, geographic information corresponds to the country of origin of the studied material as reported in the original publication; records are not georeferenced and no coordinates are provided. The country of origin is available for 71,864 records (33.7%) from 172 countries. Most records without a country derive from classic compilations, notably Fedorov (1969), which do not report the origin of the material; the country is generally recovered when a record is verified against the original publication (97.2% of verified records include it, compared with 9.6% of unverified ones).

Taxonomic Coverage

Vascular plants (Tracheophyta): lycophytes, ferns, gymnosperms and angiosperms. The release includes 386 families, 7,419 genera and 64,207 taxa; 197,076 records refer to species and 16,351 to infraspecific taxa. Records identified only at genus level are not included in this release.

Temporal Coverage

Project Data

ChromoDB is a long-term project of the Botany Section of the Universitat de Barcelona (research group BioC-GReB; Institut de Recerca de la Biodiversitat, IRBio) aimed at the continuous curation of published chromosome numbers of vascular plants. It derives from CromoCat, a chromosome database of the vascular flora of the Catalan Countries maintained for more than 25 years, which distinguished counts made on material from the region (Cro-In) from counts of the same taxa based on material from elsewhere (Cro-Out). The progressive growth of Cro-Out into a large body of worldwide data made the move to global coverage natural. Other antecedents of the group are DCDB, a worldwide chromosome database of tribe Delphinieae (Ranunculaceae) started in the late 1990s, and CromoPar, an international project on the chromosome diversity of the flora of Paraguay. Rather than aggregating as many counts as possible, the project aims to progressively transform scattered and heterogeneous literature data into records that are taxonomically updated, bibliographically traceable and scientifically reusable, and to make the degree of curation of each record explicit.

The personnel involved in the project:

Sampling Methods

Data were not obtained by field sampling but compiled from published sources: original papers, chromosome-number series (e.g. IAPT/IOPB Chromosome Data and regional series such as those published in Lagascalia, Flora Mediterranea, Bocconea and Anales del Jardín Botánico de Madrid), classic compilations (e.g. Fedorov 1969; Index to Plant Chromosome Numbers) and other databases (e.g. CCDB). For each record, the provenance (the compilation through which it first entered the database) is kept and updated when the original publication is checked. Chromosome numbers are included when the source explicitly reports an n or 2n value; ChromoDB does not itself convert genome-size, flow-cytometry or other indirect measurements into chromosome numbers. Values are retained as reported in the source, including approximate counts (e.g. “ca. 60”) and other notation used by the authors. The derivation of the chromosome number is recorded internally in ChromoDB. Records whose chromosome number is classified as inferred under the INFERRED: CL category are excluded from this GBIF release. A record represents one published chromosome-number result for one taxon, one bibliographic source and, when reported, one country of origin of the material. When a publication reports several populations of the same taxon from the same country with the same result, they are represented by a single record; separate records are created when the source, taxon, chromosome result or country differ. Notes from the source or from the curation process (e.g. counts reported as somatic numbers by Fedorov, or counts reassigned by later authors) are given in occurrenceRemarks.

Method step description:

1. 1) Compilation of chromosome-number reports from original publications, series, compilations and databases, recording the provenance of each record. 2) Recording of the taxon identification used in the source, the chromosome number (n or 2n) as reported and, when available, the country of origin of the studied material. The identification used in the source is retained in ChromoDB and exported to Darwin Core as verbatimIdentification; minor orthographic corrections and standardisation of author abbreviations may be applied when they do not alter the taxonomic interpretation. 3) Collapsing of equivalent populations into single records when taxon, bibliographic source, chromosome result and country are identical. 4) Independent taxonomic reconciliation of the published identification against Plants of the World Online (POWO) and the World Checklist of Vascular Plants (WCVP). The taxon selected through this reconciliation is exported as scientificName and acceptedNameUsage, and acceptedNameUsageID provides the corresponding POWO identifier. 5) Bibliographic standardisation and, whenever possible, verification of the chromosome record against the original publication; assignment of a confidence level documenting the degree of verification. 6) Selection of records meeting the GBIF inclusion criteria, mapping to Darwin Core and publication through the IPT of GBIF Spain. Corrections and additions are maintained continuously in ChromoDB and incorporated into subsequent GBIF releases.

Bibliographic Citations

1. Simon J, Bosch M, Blanché C (2023) CromoCat: Chromosome Database of the Vascular Flora of the Catalan Countries—25 years. In: Garcia S, Nualart N (Eds) Plant Genomic and Cytogenetic Databases. Methods in Molecular Biology 2703. Humana, New York, 131–160. https://doi.org/10.1007/978-1-0716-3389-2_11
2. Bosch M, López-Pujol J, Blanché C, Simon J (2023) DCDB: Chromosome Database of Tribe Delphinieae (Ranunculaceae): Structure, Exploitation, and Recent Development. In: Garcia S, Nualart N (Eds) Plant Genomic and Cytogenetic Databases. Methods in Molecular Biology 2703. Humana, New York, 173–192. https://doi.org/10.1007/978-1-0716-3389-2_13
3. Simón J, Franco D, Fernández V, Soloaga M, Daviña J, Honfi A, Rovira AM, Molero J (2000) Proyecto CROMOPAR: estado actual de conocimientos de la diversidad cromosómica de la flora paraguaya. II Jornadas de Biología del Mercosur, Asunción (Paraguay).

Additional Metadata