Kew's Plants of the World Online accepts 43 species of Capsicum. Five of them carry cultivated peppers, so 38 species are wild, and most of those have never been grown outside a research plot. The 2022 monograph by Barboza and co-authors in PhytoKeys is the current reference for all of them, and it makes plain how thin the underlying data still is.

How many wild Capsicum species are there?

Thirty-eight, on the Kew count, and the number keeps moving upward. Carrizo García and colleagues sampled 34 of roughly 35 recognized species for their 2016 phylogeny and recovered eleven well-supported clades, four of them holding a single species. Six more species entered the literature between 2019 and 2022. The older hedge of "30 to 45 species" came from guessing across an unsettled taxonomy; there is now a published list to point at instead, laid out in our Kew species list.

Where the wild species live

Brazil holds the largest share. Fourteen accepted species occur nowhere else, concentrated in the Atlantic Forest of Rio de Janeiro, São Paulo and Minas Gerais. Bolivia holds a second cluster, the Andean slopes of Ecuador, Peru and Colombia a third. One species sits on an island. The genus originated along the Andes of western and northwestern South America, and Carrizo García's group traced its expansion clockwise around the Amazon basin from there.

The species growers and breeders ask about

Every species the earlier version of this page listed appears below, with the record corrected where it needed correcting.

Species.Range.What is actually established.
C. chacoense.Bolivia to Paraguay and northern Argentina.Source of the Bs2 bacterial spot resistance gene, from accession PI 260435; pungent and non-pungent forms both occur.
C. eximium.Bolivia to northwestern Argentina.Purple corolla; sits in the purple-flowered group with C. pubescens, and crosses within it.
C. cardenasii.Western Bolivia.Self-incompatible, so a single plant sets nothing. Sold as ulupica. No frost-hardiness data supports the claim often attached to it.
C. tovarii.Central Peru.Its own monotypic clade. Affinities disputed between the purple-flowered group and the baccatum complex. Assessed as Endangered.
C. rhomboideum.Mexico to northern Venezuela and northern Peru.Yellow flowers, non-pungent fruit, earliest-diverging lineage in the genus.
C. galapagoense.Galápagos, endemic.Endangered: extent of occurrence about 8,000 square km, area of occupancy 56 square km. Goats, pigs and invasive plants drive the decline.
C. lanceolatum.Central Mexico to Honduras.Endangered cloud-forest species with non-pungent fruit. Bosland and González rediscovered it in a Guatemalan reserve in 2000.
C. flexuosum.Southeastern Brazil to northeastern Argentina.Both pungent and non-pungent berries recorded. Cold-tolerant relative of interest to breeders.
C. friburgense.Rio de Janeiro state, Brazil.Critically Endangered. Known from a small area hit by fires, floods and mudslides.
C. mirabile.Eastern Brazil.Atlantic Forest clade. Almost no cultivation or germination data exists.
C. parvifolium.Northern Colombia to Venezuela and northeastern Brazil.Dry-region species; the monograph records pungent and non-pungent fruit in the group.
C. rabenii.Central and southern Brazil to Paraguay.The accepted name for what seed lists still call C. praetermissum.
C. caatingae, C. longidentatum.Northeastern Brazil.Described in 2011; dry Caatinga biome; understudied.
C. mirum, C. piuranum.São Paulo; northwestern Peru.Both Critically Endangered, both described since 2019, both known from tiny populations.

What the monograph settled

Three name problems worth fixing in your own records. C. praetermissum is a synonym of C. rabenii. C. anomalum belongs to a different genus altogether and takes the name Tubocapsicum anomalum. The wild bird pepper that everyone labels C. annuum var. glabriusculum appears in Kew under var. aviculare, and this database still uses the older epithet. Our tepin and pequin page works through that last one.

What nobody has measured yet

The gaps are specific, and worth naming rather than gesturing at. No published trial reports days to maturity for any wild Capsicum species. Germination research covers the wild bird peppers and effectively stops there, which is why the protocols in our wild pepper growing guide lean on grower records for everything else. Pollination biology is largely unstudied outside the crop species and their close relatives. Capsaicinoid profiles exist for a handful of species and nothing like the genus.

Conservation data is the starkest gap. The authors graded every taxon they treated against IUCN criteria. Twenty came out Least Concern. Ten landed at Endangered, four at Critically Endangered, four at Vulnerable and four at Near Threatened. Those are the authors' own assessments against IUCN criteria, not Red List entries, and almost none have gone through formal review. For a genus this economically important, that is a remarkable hole.

What is stopping the research?

Access rules, mostly, and then money. Capsicum does not appear in Annex I of the International Treaty on Plant Genetic Resources, the list that puts a crop into the multilateral exchange system. Potato and eggplant made the list; peppers did not. Every international transfer of pepper germplasm therefore runs on bilateral agreements and national access law rather than a standard material transfer agreement, which slows collection and repatriation alike.

Movement of seed is tightly held for a second reason. APHIS excludes pepper and tomato seed from the Small Lots of Seed permit, so imports into the United States need a phytosanitary certificate carrying an additional declaration and virus testing. That rule targets tomato brown rugose fruit virus, and it applies to a researcher's 20 seeds exactly as it applies to a commercial lot. Habitat loss, remote collecting sites, and thin funding for non-commercial work finish the picture.

Where the material is held

Four collections carry most of the accessible wild Capsicum. The IPK genebank at Gatersleben in Germany issues the CAP accession numbers you see on wild seed, a detail growers routinely misattribute to the Chile Pepper Institute. USDA GRIN issues PI numbers. The Centre for Genetic Resources at Wageningen issues CGN numbers. EMBRAPA in Brazil holds the largest collection of the Brazilian endemics, and the monograph's second author works there. Genesys aggregates most public holdings, which makes it the right first stop when you want to know whether a species exists in any public collection at all.

Sources & Further Reading