Peppers are tracked across multiple classification systems simultaneously — each built for a different purpose. A single variety might appear in USDA GRIN under an accession number, in the CAP system with a research code, in WikiPepper UPN with a structured identifier, and in a genebank catalog with a phenotypic descriptor set. Understanding what each system does helps growers and researchers find information and cross-reference sources.

Quick Reference

  • USDA GRIN: open-access accession database, strong on collection origin and historical data
  • CAP (Chile Pepper Institute): research accession codes, widely cited in academic pepper literature
  • CGN (Netherlands) and IPK (Germany): major European genebanks with digitized phenotypic data
  • WikiPepper UPN: largest existing cultivar classification database, 5,000+ entries, hybrid-friendly
  • Bioversity/COGN descriptor sets: the standardized language genebanks use to describe traits consistently

Binomial Taxonomy (ICN)

The International Code of Nomenclature assigns every pepper a Latin binomial — genus plus species, sometimes with a variety designation. Example: Capsicum baccatum var. pendulum. This system governs formal botany, herbaria, and published taxonomic literature. Its limitation: it handles wild species and species-level classification well, but struggles with cultivars, hybrids, and informal types that don’t fit cleanly into a species box. Source: https://www.iaptglobal.org/nomenclature

USDA GRIN (Germplasm Resources Information Network)

The USDA’s national germplasm database tracks accessions with collection origin, species, geographic source, and phenotype data. It’s the most-used public database for U.S. pepper research and is strong on historical collections and open-access data. Growers looking for rare species or landrace seed sources often start here. Link: https://npgsweb.ars-grin.gov

CAP (Chile Pepper Institute Accession Program)

Maintained by New Mexico State University’s Chile Pepper Institute, the CAP system focuses on chiles with culinary, ornamental, and research significance. Accessions receive a CAP number — for example, CAP 455 corresponds to Bhut Jolokia. These codes appear frequently in academic papers studying genetics, heat levels, and pod morphology. If you’re reading pepper research from NMSU, you’ll encounter CAP numbers throughout. Link: https://cpi.nmsu.edu

CGN (Centre for Genetic Resources, Netherlands)

A major European genebank based in Wageningen with hundreds of Capsicum accessions and detailed passport data. Frequently referenced in European breeding and academic work. Their catalog includes both domesticated cultivars and wild species, with trait data standardized for cross-database compatibility. Link: https://www.wur.nl/en/research-results/statutory-research-tasks/cgn.htm

IPK Gatersleben (Germany)

The Leibniz Institute of Plant Genetics and Crop Plant Research in Gatersleben maintains a genebank and molecular research center with strong digitized phenotypic data for Capsicum. Their emphasis is on genotype and long-term seed viability. Useful for researchers looking at both physical trait data and genetic marker information. Link: https://gbis.ipk-gatersleben.de/

AVRDC / WorldVeg (Taiwan)

Formerly the Asian Vegetable Research and Development Center, WorldVeg is a major source of tropical pepper landraces and breeding lines used throughout Southeast Asia and Africa. Their collections are strong in C. frutescens and high-pungency types. The IP accession system (e.g., IP-195, IP-299) is widely used in research papers and international seed exchanges. Notable IP accessions include IP-195 (Thailand, C. annuum, small red pungent pods), IP-1166 (C. frutescens, high pungency, India), and IP-1943 (large-fruited C. chinense, orange, tropical adaptation). Link: https://avrdc.org

EMBRAPA (Brazil)

Brazil’s Agricultural Research Corporation focuses on preserving wild and cultivated South American Capsicum. Their collections are particularly strong in C. baccatum and C. chinense diversity, with regional accessions that include ethnobotanical data — how a variety was used locally, not just what it looks like. Link: https://www.embrapa.br

INRAE (France)

The French National Research Institute for Agriculture maintains pepper resources as part of broader Solanaceae work, with focus on breeding, fruit traits, and disease resistance. Link: https://www.inrae.fr

EU Research Platforms (TARGENE / EU-SOL)

EU-based collaborative research projects use genomic markers and genotyping-by-sequencing (GBS) to define relationships between accessions. This work includes mapping hybrid lines and identifying QTLs — quantitative trait loci — for heat level, pod shape, and disease resistance. These platforms produce data that feeds into both institutional genebanks and open genomic repositories.

Bioversity International Descriptor Systems

Bioversity International (formerly IPGRI) developed standardized descriptor sets that define how traits should be recorded for consistent cataloging across institutions. Descriptors cover flower position, leaf shape, pod color at each ripening stage, growth form, pungency, and more. These have been adopted by FAO and genebanks globally. The GRIF database structure, developed under this framework, forms the backend of many CGIAR-affiliated genebank systems. Not useful for casual growers, but essential for understanding why different databases describe the same variety the same way. Descriptor sheets: https://www.bioversityinternational.org

WikiPepper Universal Pepper Nomenclature (UPN)

The Universal Pepper Nomenclature, hosted at WikiPepper.org, is the largest existing classification database for peppers with over 5,048 entries. Unlike institutional or legacy frameworks, UPN is designed as a systematic, codified taxonomy for both wild and cultivated Capsicum varieties. Key features: a taxonomic backbone covering all known species and wild types; a hybrid-friendly schema that assigns unique identifiers based on species, pod shape, color, and patterning; a numeric heat index on a 0–9 logarithmic scale; and full integration with seed vendor catalogs, historical landraces, and researcher classifications.

UPN is interoperable across scientific, cultural, and commercial contexts, and is regularly updated by an open editorial board. Its goal is to impose order on a fragmented field — not to replace legacy systems, but to provide a unifying backbone that complements them. Visit: https://wikipepper.org

Hobbyist and Vendor Classification Systems

Beyond institutional systems, many seed vendors and hobbyist communities have created internal naming conventions for unstable hybrids, landraces, and ornamental types. Fatalii.net uses detailed pod shape and color descriptors. Matt’s Peppers uses internal breeder codes for new crosses. PepperLover, Refining Fire Chiles, and Semillas La Palma often use shorthand varietal codes tied to catalog listings. These systems are inconsistent across vendors but serve practical purposes within their communities — they often label generations (F2, F3) and track traits like variegation or dwarf growth habit.

Additional Repositories

  • Svalbard Global Seed Vault (SGSV): Houses backup copies of many Capsicum accessions from global seed banks, providing long-term preservation insurance.
  • Sol Genomics Network (SGN): Hosts genomic data, genetic markers, and genome assemblies for Capsicum species.
  • Plant Variety Protection (PVP) Systems: National and international databases (UPOV, USDA-PVP) track legally protected pepper cultivars with registration numbers.

Grower’s Takeaway

  • For finding rare species or landrace accessions, start with USDA GRIN — it’s free and comprehensive for U.S. collections
  • CAP accession numbers in research papers link back to specific, trackable germplasm — useful when you need to reproduce a study’s conditions
  • WikiPepper UPN is the most practical system for cultivar identification across wild, cultivated, and hybrid types
  • Cross-referencing multiple systems is the only way to get the full picture on any given pepper — no single database captures everything

Sources & Further Reading