The Rectification of Pepper Names
“When a name is not correct, speech will not be in order. When speech is not in order, then nothing will be accomplished.”
— Confucius, Analects, 13.3
A pepper is not just a pepper. It is a history of selection, a signal to the palate, a source of heat, color, and culture., much less the 19 different version of the work “pequin” used across the world. In the English-speaking world, we cannot agree whether it is a chili, chile, chilli, or just a pepper. Yet in modern seed exchange, online markets, social media groups, and even academic databases, the chaos of nomenclature grows like weeds. Names are duplicated, mutated, translated, and misapplied. “Purple Tiger” may refer to a half dozen different cultivars. “Jalapeño” might mean a landrace from Veracruz or a supermarket F1. The result is miscommunication, mistrust, and the breakdown of both knowledge and commerce.
This project—Universal Pepper Nomenclature (UPN)—is a proposal for a more rigorous, intuitive, and flexible way of naming and tagging chili pepper varieties. It is not meant to replace binomial Latin names or government-controlled identifiers like those used in the CGN (Centre for Genetic Resources, Netherlands) or CAP (Chile Pepper Institute Accession Passport) databases. Rather, it exists alongside them, designed to serve breeders, sellers, researchers, growers, and collectors who need a way to quickly recognize and distinguish peppers based on meaningful, observable traits.
Like Confucius’ vision of restoring social harmony through linguistic clarity, this system aims to create order through classification: names that reflect form, color, hybrid status, and species, all embedded in a compact, semi-intuitive code. In this system, a pepper like C. chinense × C. baccatum, ripening to striped peach with a wrinkled bonnet form, receives a code that says exactly what it is, not just what it’s called.
Before we can grow well, share well, and trade well, we must name well.
The Nature of Taxonomies & Why This One?
Taxonomy is the art of naming things in a way that reflects their nature and relationships. In biology, it serves as a tool for ordering the natural world: genus, species, cultivar. But in practice—especially with domesticated plants like Capsicums—taxonomic categories often lag behind the lived experience of growers, seed savers, and collectors.
Botanical Latin provides a skeleton. Institutions like the CGN (Centre for Genetic Resources, Netherlands) and CAP (Chile Pepper Institute Accession Passport) layer on accession numbers, breeder history, and passport data. These systems are valuable—but they are designed for archivists, not for gardeners. They track where a seed came from, but not always what it is.
For example, CGN20681 tells you this accession came from a botanical garden in Ecuador. But it doesn’t tell you whether it’s purple-blushed, whether it grows upright, or whether it’s a scorpion-style chinense crossed with a waxy baccatum. That kind of phenotypic resolution—form, color, pattern—is missing. And that’s where most of the naming mess happens.
You wouldn’t walk into a nursery and ask for CGN21550. You’d ask for “a purple ornamental with upright fruit and medium heat.” But what you get might be a C. annuum, a C. frutescens, or some hybrid named after a cryptid or a cartoon character.
The Universal Pepper Nomenclature (UPN) provides a way to bridge this gap. It works orthogonally to Latin naming—built around the features that matter to growers, breeders, and buyers: shape, ripening color, species lineage, and patterning. It condenses all this into a short, interpretable string—a fruit’s passport in code form.
Unlike CGN or CAP, this system is not centrally managed, nor anchored in institutional archives. It is a folk taxonomy in the best sense: rigorous, recursive, expandable—and open to anyone paying attention to what peppers are rather than just what they’re called.
UPN – An Overview
The Universal Pepper Nomenclature (UPN) system encodes a pepper’s key identity traits into a compact alphanumeric string. It’s designed to be easily human-readable, scalable, and programmatically sortable. The structure draws on taxonomy, phenotype, and breeding lineage—all in one place.
It should also resolve the confusion over trade names, or the interchangeability of “Bhut Jolokia” versus “Ghost Pepper” varieties. The names may differ, but the UPN won’t lie. Typing a UPN into a search engine will save untold minutes.
Here’s the basic structure:
S-C-P-F-W-H-##
| Field | Meaning | Description | |
| S or S x S | Species Code | 1 or 2-letter code (e.g. A = C. annuum, C = C. chinense) or hybrid (A×C). Within category, the ordering will always be alphabetical for consistency. | |
| C or C x C | Dominant final color (O=orange; R=red). Color is a nonexclusive trait, with multiple codes possible between dashes. By convention, it should be alphabetical – e.g., chocolate candy cane is BR (brown/chocolate and red. If each fruit is liable to be a different color unto itself, such as with Aji Omnicolor, it would then be listed as M for multicolor. | ||
| PT | Patterned Trait Code |
|
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| F | Fruit Form | 1-letter code for shape/type (B = bell, H = habanero-style, etc.) | |
| H | Heat | A 1-digit code for (see schema below). | |
| ## | Serial Identifier | A unique 2-digit or alphanumeric code assigned to distinguish entries sharing qualities. It is only necessary when all other categories match. |
Example Code: C-H-R-SWWR-7-17
- C = Capsicum chinense
- H = Habanero-style shape
- R = Red when mature
- SWWR = Striped pattern and wrinkled traits
- 7= Heat between 100,000 and 350,000 Scoville Heat Units (SHU)
- 17 = Entry #17 of the type C-H-R-STWR-7
This pepper could easily be something like a Red Savina or a similar wrinkled, red chinense cultivar with a striped immature phase.
The UPN format solves the problem of ambiguity. Instead of “Purple Tiger” (which might refer to dozens of unrelated peppers), you get A-P-VR-Y-05—clearly denoting a variegated purple annuum with unusual form.
UPN System in Practice
Below is a table showcasing selected pepper varieties from – foe example – Semillas La Palma (www.semillas.de), each accompanied by its corresponding UPN code and a brief description.
| Pepper Variety | UPN Code | Description |
| 7 Pot Bubblegum Yellow | C-H-Y-UN-8-01 | Capsicum chinense; matures to yellow; no distinct pattern; habanero-type shape; domesticated; non-hybrid. |
| Aji Fantasy | B-N-Y-UN-4-01 | Capsicum baccatum; matures to yellow; no distinct pattern; gourd/pear shape; domesticated; non-hybrid. |
| Sugar Rush Stripey | B-M-ST-Y-03 | Capsicum baccatum; multicolored stripes at maturity; striped pattern; long/thin shape; domesticated; hybrid. |
| Black Pearl | A-P-BB-N-23 | Capsicum annuum; matures to purple; black blush pattern; unusual form; domesticated; non-hybrid. |
| MOA Scotch Bonnet | C-Y-UN-N-05 | Capsicum chinense; matures to yellow; no distinct pattern; habanero-type shape; domesticated; non-hybrid. |
Major Domesticated Species:
- A – Capsicum annuum
- B – Capsicum baccatum
- C – Capsicum chinense
- F – Capsicum frutescens
- P – Capsicum pubescens
Minor/Wild Species (aligned to name and commonality as much as possible):
| Code | Species |
| D | C. dimorphum |
| E | C. exium |
| G | C. galapagoense |
| H | C. hunzikerianum |
| I | C. caballeroi |
| J | C. flexuosum |
| K | C. cardenasii |
| L | C. lanceolatum |
| M | C. chacoense |
| N | C. scolnikianum |
| Q | C. campylopodium |
| R | C. rhomboideum |
| S | C. schottianum |
| T | C. tovarii |
| U | C. praetermissum |
| V | C. villosum |
| W | C. bushingii |
| X | C. friburgense |
| Y | C. eshbaughii |
| Z | C. lanceolatum variant |
Sub-species:
For subspecies, we’ll use the AxA format with the assigned single-character codes. Examples:
- A×C – Capsicum chinense × Capsicum annuum (A before C because it is alphabetical)
- B×F – Capsicum baccatum × Capsicum frutescens
- D×F – Capsicum frutescens × Capsicum chacoense
This system maintains clarity and consistency, allowing for straightforward identification of species and their subspecies. Wild and domestic status can be inferred or researched further. More species and hybrids can be added.
Pod Form (F)
This single-letter code classifies the overall shape of the fruit. If multiple forms are known for a cultivar, use the dominant marketed type.
| Code | Form |
| A | Aji/ Tapered |
| B | Bell |
| H | Habanero-type |
| L | Long / Tapered |
| S | Short / Squat |
| T | Tomato / Round |
| W | Wedge / Lantern |
| P | Pequin / Small bullet |
| R | Rocoto / Ovate |
| U | Unusual / Unclassified |
| C | Curled / Twisted |
| M | Mushroom / Bonnet |
| F | Apple / Thick blunt type |
| N | Long and noodly |
Major Color at Maturity
Color codes are not mutually exclusive – can select multiple color codes within the same dash. Conventionally, in alphabetical order.
| Code | Color | Notes |
| R | Red | Standard red, including deep reds |
| C | Crimson / Burgundy | Darker red hue, bordering burgundy |
| O | Orange | Bright or standard orange |
| T | Peach / Salmon / Pastel | Lighter warm tones |
| Y | Yellow | Lemon, bright, or canary yellow |
| G | Green (mature) | Fully ripe but remains green |
| B | Brown / Chocolate | Deep brown phenotypes |
| A | Caramel | Reddish-brown or warm brown ripening |
| D | Gold | Metallic yellow/golden ripening |
| P | Purple | Dark pigmentation often from anthocyanin |
| Z | Pink | Pale red / unstable pink tone |
| W | White / Cream | Includes ivory and pale-yellow phenotypes |
| K | Black (mature) | Fully black phenotypes (rare) |
| M | Multicolor / Irregular | Unstable or transitional coloration |
| U | Blue | Rare, mostly immature state / anthocyanin |
| N | No color / Transparent | Rare ornamental types or waxy phenotypes |
Patterned Trait (PT)
|
Code |
Pattern / Trait | Description | Examples |
| ST | Striped | Long vertical lines of alternating colors | Fish Pepper, Trifetti |
| FL | Flecked / Speckled | Small dots or irregular spots of different colors | Numex Twilight, Calico |
| MB | Marbled / Swirled | Irregular blending of multiple colors, often swirled or cloud-like | Purple UFO, Aji Omnicolor |
| BL | Blotched | Large irregular color splotches | Numex Twilight, Bolivian Rainbow |
| SP | Splashed | Brush-stroke-like smears | Experimental hybrids, chimeras |
| GH | Ghosted / Shadowed | Faint halo-like discoloration, especially near stem or tip | Early ripening Aji types |
| MO | Mosaic / Mottled | Patchy, virus-like color breaks or genetic mosaicism | Calico, virus-affected plants |
| BD | Banded | Horizontal rings or bands of color (rare) | Rare mutations or unstable hybrids |
| CK | Corked | Rough, scar-like cracking on skin (often brown or tan) | Jalapeño, Criolla de Cocina |
| NV | Netting / Veining | Reticulated network of thin lines on skin | Overlaps with corking |
| WT | Warty / Bumpy | Raised blister-like texture | Carolina Reaper, Bhut Jolokia |
| UN | Smooth and Glossy | Undistinguished; slick, reflective skin | Aji Fantasy, Padrón |
| MT | Matte / Powdery | Dull, waxy finish | Wild or pubescens types |
| BC | Bleeding Calyx | Pigmentation from the calyx “bleeds” onto the pepper pod | BBG7 Bleeding, Bleeding Borg |
| CC | Colored Calyx | Calyx itself is red, purple, or black | Purple UFO, BBG7 hybrids |
| TR | Translucent Skin | Skin appears semi-transparent, with interior structure visible | Glass Gem types, Pimenta da Neyde |
| MR | Multicolor Ripening | Pod transitions through 3–5 distinct colors during ripening | Numex Twilight, Aji Omnicolor |
| PA | Persistent Anthocyanin | Purple/black coloring remains through full ripeness | Pimenta da Neyde, Purple Jalapeño |
| CI | Color Inversion | Ripe fruit is darker than unripe (e.g., starts red, turns black) | BBG7 hybrids, F3–F6 crosses |
| BT | Bicolor Tips | Tip of pod is a different color than base | Some Chocolate Ghosts |
| SR | Segmented / Ribbed Coloring | Color divided sharply along natural pod segments | C. chinense, rocoto crosses
|
| TA | Tail | Scorpion tail emanating from the bottom of the fruit | Butch ‘T’ Scorpion |
Perceived Heat Scale (T)
Peppers are enjoyed in large part for their heat and flavor profiles. Scoville Heat Units have their benefits as a measurement but vary from pepper to pepper within a plant, and plant to plant. They are also one to seven digits for peppers, making them cumbersome. The ranges below are based on arbitrary but reasonable categorizations drawn roughly at well-known pepper types and span only 0-9.
We call this the Perceived Heat Scale (PHS). It is designed to show how dramatically the heat of a pepper increases as it moves up the SHU range. Each unit on the scale represents a large increase in perceived heat, making it easier to compare and classify peppers with varying heat intensities.
|
Scale (0-9)
|
Heat Range (SHU) | Pepper Examples | Description |
| 0 | 0 – 500 | Bell Pepper, Banana Pepper | No heat, sweet, mild flavors |
| 1 | 500 – 1,000 | Padrón, Sweet Italian | Very mild heat, barely noticeable |
| 2 | 1,000 – 2,500 | Anaheim, Pasilla | Mild heat, often used for cooking or flavor |
| 3 | 2,500 – 5,000 | Jalapeño, Fresno | Mild-medium heat, common in salsas and dishes |
| 4 | 5,000 – 15,000 | Aji Amarillo, Serrano | Medium heat, sharp bite |
| 5 | 15,000 – 50,000 | Habanero, Thai Bird’s Eye | Hot, fruity, with a noticeable heat kick |
| 6 | 50,000 – 100,000 | Scotch Bonnet, Pequin | Very hot, intense heat with lingering burn |
| 7 | 100,000 – 350,000 | Ghost Pepper, 7 Pot | Extremely hot, intense burn that lingers |
| 8 | 350,000 – 1,000,000 | Carolina Reaper, Infinity Pepper | Super-hot, mouth-burning, can be overwhelming |
| 9 | 1,000,000+ | Pepper X, “World’s Hottest” | Ultra-hot, used in extreme sauces or challenges |
Serial Number
The 2-digit serial number is meant to encompass accessions sharing the foregoing characteristics of the pepper but is distinct in some other way, such as lineage, degree, or something else to making two peppers clearly distinct from one another. One hundred possibilities may be too broad, but ten is already too few for a handful of Ghosts, etc. experiencing feverish breeding activity worldwide.
Glossary of Terms
| Term | Definition |
| UPN | Universal Pepper Nomenclature — a compact, structured code representing a pepper’s color, pattern, shape, heat, and species lineage. |
| Code (S) | A single-letter code for species of the genera of Capsicum (e.g., A = annuum, B = baccatum). Hybrids are denoted using the S×S format (e.g., A×C). |
| Fruit Form (F) | A single-letter code for the shape or form of the fruit, such as H = habanero-style, B = bell, L = long/thin, U = unusual. Also, non-exclusive. Also, by convention, alphabetical. |
| Color (C) | The dominant color the fruit reaches when fully ripe. E.g., R = red, Y = yellow, B = brown. If the fruits peppers are each liable to be a different color, it would be listed as multicolored. If a single fruit is liable to be known colors, the color code between dashes can be multiples such green and orange: “OG.” |
| Patterned Trait (PT) | 2-letter code(s) describing color pattern or skin surface characteristics (e.g., ST = striped, VA= variegated, BB = black blush, FL = flecked). |
| Heat (T) | 0-9 scale (explained below). It is semi-intuitive and ordinal. |
| Serial Number (###) | A unique identifier to distinguish varieties even if they share the same phenotype. Usually 3 digits or alphanumeric for large datasets. |
UPN Administration and Submission
For the system to work, it must be universal and centralized. Multiple breeders cannot freewheel and simultaneously claim a unique number for their phenotypes. It remains to be seen who or what this centralized administration takes, but a breeder of a stable landrace or accession or cross would submit their pepper to a database for inclusion to avoid future confusion.
The model I like is the Correlates of War (COW) Dataset at the University of Michigan, which has standardized the study of wars. It has led to rigorous and agreed-upon conventions so that academics are less likely to speak at cross purposes, and data is comparable across studies. Something similar is the goal of this endeavor.
Once submitted, a registered pepper can be stripped of its status if found unstable, unoriginal, or too-similar to an existing entry.
Reserved Color and Form Codes
As the system grows, new entries may be needed. These slots are pre-reserved:
- Color Codes Reserved: E, X, Q, J
- Form Codes Reserved: E, X, Q, D, N
These letters are held in reserve to prevent re-encoding existing traits under new codes.
Guidelines for Future Expansion
- Numeric codes (e.g., 1, 2, 3) are used once A–Z is exhausted.
- Extended form or pattern traits may be added using modular suffixes or a second pattern field (P2) in future versions. Heat profile (H) may also adopt a different scale or convention.
- Addenda such as wild or domesticated can follow the UPN as descriptors, though it can often be apparent from the species, context, or additional research.
- Optional fields for chill hours, flowering time, and capsaicinoid type may be appended for breeder use, e.g.:
- C-H-R-ST-H-7-01-F75-C3 → 75-day fruiting, capsaicinoid profile class 3
Comparison with CGN, CAP, and Informal Naming Systems
I cannot cover all naming conventions and systems for peppers. That is part of the problem I intend the UPN to solve. However, I will discuss a couple of systems in brief to demonstrate the advantage of the UPN.
The CGN system promulgated by the Center for Genomic Research in the Netrherlands issues – like others – a assigns accession numbers such as CGN 21500 to pepper varieties as part of a broader seed conservation and genetic research effort. While invaluable for global germplasm tracking, CGN codes are:
- Opaque to most growers and consumers.
- Non-descriptive of phenotype or trait.
- Unsuitable for marketing or field reference.
They also typically refer to raw, unselected accessions, not stabilized commercial or breeder-selected lines.
The CAP (Chili Institute Accession Passport) system, created by the New Mexico State University Chile Pepper Institute, catalogs peppers collected from the wild and through landrace exchanges, with a format like CAP 501. These records are:
- Focused on preservation and origin.
- Valuable for scientific and ethnobotanical study.
- Not updated to reflect cultivar development or selection.
- Often limited to New Mexican and Andean accessions.
CAP also does not attempt to describe shape, heat, color, or consumer-relevant traits.
It draws on folk and commercial naming. Most growers encounter peppers under names like: “Chocolate Ghost,” “Striped Peach Scorpion,” and “Purple UFO.”
These names are:
- Non-standard (multiple cultivars share names).
- Regionally or vendor-dependent.
- Unstable, especially in early generation lines.
- Often misleading, e.g., a “Red Ghost” that is neither red nor a true Bhut Jolokia.
Vendors regularly sell different genotypes under identical names or vice versa. This practice makes comparison and tracking nearly impossible, especially across languages and borders.
The Advantage of UPN
Unlike CGN or CAP, the Universal Pepper Nomenclature is:
- Trait-centered rather than origin-centered.
- Scalable to new cultivars and phenotypes.
- Compatible with formal and informal systems but independent of them.
- Searchable and sortable for online databases and breeding logs.
It complements traditional systems while solving the gap for growers, breeders, and marketers