The story of chile pepper botany is a long and complicated one. The genus Capsicum, as a grouping within the family Solanaceae (nightshade family), above the level of the species, was already recognized and named by Carl von Linné (Carolus Linnaeus) at the beginning of botanical systematics.

Species, however, were still often named after dominant morphological characteristics, that is, according to the looks of the chilli (especially the fruit). Sometimes, other factors were used to name the species.

Thus, we got the name Capsicum annuum from Linnaeus, who thought that this widely spread species of chilli was an annual plant. (It actually isn’t, at least in the tropics where it has its home.)

Similarly, Nikolaus von Jacquin named the species Capsicum sinense (or as it is now spelled, Capsicum chinense) “after its homeland,” China. This was a misnomer; this species is Caribbean rather than Chinese…

Chilli Groups ("Clades")

In recent years, with genetic advancements and the discovery of more wild species, knowledge about the chilli species has greatly improved.

The current state of knowledge is this:

There are eleven different “clades” (botanical groupings), which contain the different species

• Andean Clade
• Capsicum rhomboideum (Dunal) Kuntze
• C. lanceolatum (Greenm.) Morton & Standl.
• C. geminifolium (Dammer) Hunz.
• C. dimorphum (Miers) Kuntze
• C. lycianthoides Bitter
• C. hookerianum (Miers) Kuntze
• And 2-3 further species
• Caatinga Clade
• Flexuosum Clade
• Bolivian Clade
• Longidentatum Clade

• Atlantic Forest Clade

• C. campylopodium Sendtn.
• C. cornutum (Hiern) Hunz.
• C. friburgense Bianch. & Barboza
• C. hunzikerianum Barboza & Bianch.
• C. mirabile Mart. ex. Sendtn.
• C. pereirae Barboza & Bianch.
• C. recurvatum Witasek
• C. schottianum Sendtn.
• C. villosum Sendtn.
• And 1-2 more species
• Purple Corolla Clade
• Pubescens Clade
• Tovarii Clade
• Baccatum Clade
• Annuum Clade

For the Atlantic and Andean Forest clades, the included species are mentioned above because they are of such great interest to botanists due to their species richness. Where one finds so many species, a plant group is likely to have a center of origin. Thus, one can assume that the chile peppers originally developed the most in Central America and the Andes in northwestern South America (Andean clade) and the coastal rainforest of the Brazilian Atlantic (Atlantic Forest clade).

These wild species and origins are interesting academically and as genetic resources, but domesticated species are of much greater concern for us as growers and eaters of chilli.

Domesticated Species

Domesticated species of chilli are:

• Capsicum annuumL.
• Capsicum chinenseJacq.
• Capsicum frutescensL.
• Capsicum baccatumL.
• Capsicum pubescensRuiz & Pav.

Botanical science has found things to be a bit more complicated here, too.

C. pubescensis its own clade in the above system (Pubescens clade), its major area of cultivation is in Bolivia and Peru, and it is only known as a cultivated species. (It is related to theC. tovarii, which is also the lone species in its own clade. Flexuosum and Longidentatum are also clades with only one species in them.)

C. baccatumis mainly grown in Andean South America; many of the chilli varieties known as ají belong to this species.

C. annuum, C. chinense,andC. frutescensare the most widely grown chile pepper species. They actually form the C. annuumcomplex of species (the Annuum clade in the above system) as they are not strictly separated from each other.

Source: Robert L. Jarrett et al. Capsicum – An Abbreviated Compendium. Journal of the American Society for Horticultural Science 144(1):3-22. 2019.