The genus Capsicum (Solanaceae) in Africa

The genus Capsicum (Solanaceae) includes approximately 20 wild species and 4-5 domesticated taxa commonly referred to as ‘chilies’ or ‘peppers’. The pre-Colombian distribution of the genus was New World. The evolutionary history of the genus is now envisaged as including three distinct lines leading to the domesticated taxa. The route of Capsicum to the Old World is thought to have followed three different courses. First, explorers introduced it to Europe with secondary introduction into Africa via further exploratory expeditions; second, botanical gardens played a major role in introduction; and third, introduction followed the slave trade routes. Today, pepper production in Africa is of two types, vegetable and spice. Statistical profiles on production are difficult to interpret, but the data available indicate that Nigeria, Egypt, Tunisia and Ghana are the leading producers. Production is mainly a local phenomenon and large acreage is seldom devoted to the growing of peppers. The primary peppers in Africa are C. annuum and C. frutescens.


RÉSUMÉ L E G E N R E CAPSICUM (SO LA N A CÉE) EN A FR IQ U E Le genre Capsicum (Solanacée) inclut approximativement 20 espêces sauvages et 4-5 taxa domestiqués communément dénommés 'chilies' ou 'peppers'. La répartition pré-Colombienne du genre se situait dans le Nouveau Monde. L 'histoire de Involution du genre est maintenant envisagée comme incluant trois voies distinctes conduisant aux taxa domestiqués. On pense que la migration des Capsicum vers le Vieux Monde a suivi trois voies différentes. En premier lieu, des explorateurs I'introduisirent en Europe, puis de la en Afrique, par le biais d 'explorations ultérieures en second lieu, les jardins botaniques jouêrent un rdle majeur dans cette introduction et en troisiême lieu, I'introduction suivit les routes de la traite des esclaves. Aujourd' hui, la production de Capsicum en Afrique est de deux types: légume et épice. Les données statistiques sur la production sont difficiles á interpréter, mais celles disponibles indiquent que le Nigeria, I'Egypte, la Tunisie et le Ghana sont les principaux producteurs. La production est surtout un phénomêne local et il est rare que de larges superficies soient consacrées á la culture des Capsicum . Les principaux Capsicum en Afrique sont C. annuum et C. frutescens.
Capsicum is a New World genus comprising approximately 20 wild species and 4-5 domesticated taxa (Eshbaugh, 1980a; Table 1). Hunziker (1956) divides the genus into the three sections Capsicum, Pseudoacnistus and Tubocapsicum. The monotypic section Tubocapsicum contains C. anomalum, which is native to Asia and is probably not a true pepper since it is nonpungent and has an atypical fruit for the genus. Furthermore, C. anomalum lacks certain natural chemical constituents that are present in all other New World peppers and act as predator retardants. The section Pseudoacnistus is also monotypic. Its single species, C. breviflorum, has the haploid chromosome number of n=13, whereas all true peppers are n=12. This species should probably be removed from Capsicum. Within the section Capsicum, C. ciliatum also has a chromo some number of n=13 (Pickersgill, 1977), lacks a pungent fruit, and has unusual yellow flowers atypical for the genus. These characteristics suggest that C. ciliatum is also not a true Capsicum. Other adjustments to a working concept of the genus will undoubtedly have to be made as the various taxa become better known.
The pre-Colombian distribution of the entire genus as defined in this paper is New World. Capsicum is a neotropical genus with horizontal range extensions into the subtropics and vertical * Department of Botany, Miami University, Oxford, Ohio 45056, USA. range extensions into the warm temperate regions of the Andes. The distributions of the domesticated taxa have been detailed by Heiser (1976), Pickersgill (1971 and Eshbaugh (1970Eshbaugh ( , 1979. Heiser (1976) offers a map of the probable pre-Colombian distribution of the domesticated species which provides a working hypothesis which seems reasona ble. Nonetheless, the archeological record for peppers is very incomplete. Pepper use can be dated to 7000 B.C. but the species being used is not always certain (Pickersgill, 1969a). Pickersgill (1969b) has traced the archeological record of chili peppers in Peru and indicates the presence of domesticated C. baccatum in the coastal region as early as 2500 B.C. Most species of peppers are confined to South America with an especially rich centre of diversity in Brazil. Many species of Capsicum, including C. galapagoensis (Ecuador) and C. tovarii (Peru), are narrow endemics. Perhaps the widest ranging species is C. annuum var. aviculare, the bird pepper, which occurs from the Amazon to the southern border of the United States, from Arizona to Florida and throughout the Caribbean (D'Arcy & Esh baugh, 1974).
The domesticated taxa now have a worldwide distribution but at the time Columbus discovered the New World they were much more narrowly distributed. Capsicum annuum var. annuum was Mesoamerican (Pickersgill, 1971). Capsicum bacca tum var. pendulum was restricted to zones west and east of the Andes (Eshbaugh, 1970;Pickersgill, 1971). Capsicum pubescens was a midelevational (2000 -2500 m) Andean species (Eshbaugh, 1979).
Capsicum chinense and C. frutescens were Amazonian (Pickersgill, 1971), The domesticated taxa have a unique evolution ary history for seldom have five species been independently domesticated in different geographi cal regions from one small genus. Early authors recognized and named many supposedly distinct taxa. Other workers chose to lump all the domesticated taxa under a single name C. frutescens (Bailey, 1923) or C. annuum (Shinners, 1956). Investigations of the past 25 years have given us a much clearer understanding of the taxonomy and evolution of the domesticated species. The hypothe sis that all the domesticated species arose from a single ancestor (Davenport, 1970;Jett, 1973) is no longer tenable. The opposite hypothesis that each domesticate arose from its own unique wild ancestor seems equally unlikely (Heiser et al., 1971). A more likely hypothesis (Eshbaugh, 1980b) which envisages three distinct lines of evolution leading to three subgroups is suggested by data from plant breeding (Emboden, 1961;Eshbaugh, 1964Eshbaugh, , 1975Pickersgill, 1971Pickersgill, , 1980Chennaveeraiah & Habib, 1966;Heiser & Smith, 1958;Smith & Heiser, 1957), numerical taxonomy (Pickersgill et al., 1979), and isoenzyme analyses (Jensen et al., 1979;McLeod, 1977;McLeod et al., 1979aMcLeod et al., , 1979b).
The first of these subgroups, the 'purple flowered taxa,' includes the domesticate C. pubescens and two closely related wild taxa, C. cardenasii and C. eximium.
The other two subgroups belong to the 'white flowered taxa'. One of these subgroups includes the domesticate C. baccatum var. pendulum and wild C. baccatum var. baccatum and var. tomentosum as well as C. praetermissum. Depending upon the treat ment, C. praetermissum is seen as a distinct species or variety of C. baccatum.
The third group includes a complex of three domesticated taxa, C. annuum var. annuum, C. frutescens, and C. chinense and the wild forms of C. annuum, designated var. aviculare. The domestica ted plants and most of the wild plants are easily classified into distinct species but in some wild plants the distinctions are blurred, perhaps indicating their origin in a single primitive species.
It appears that the domesticated peppers had their centre of origin in south-central Bolivia with subsequent migration and differentiation into the Andes and Amazonia (McLeod et al., 1982).
At the time the New World was discovered the only domesticated species to be widespread in the West Indies were C. annuum and C. frutescens. Exploration along the east and west coast of South America established contact with C. chinense and C. baccatum var. pendulum. Contact with C. pubescens did not come until the explorers reached the Andes. For reasons that remain unclear, the latter two taxa did not become part of the early exchange of plants between the hemispheres. Capsicum baccatum var. pendulum was introduced to the Old World in the 20th century, whereas C. pubescens is still confined to the more mountainous regions of southern Mexico, Central and South America.
The question arises, 'how did Capsicum reach the Old World and more particularly Africa?' The most likely explanation suggests several distinct routes for introduction. First, Columbus and other explorers, finding a spice as hot as anything known in Europe, collected this plant and moved it to Europe (Anghiera, 1555). From there the fruits and seeds were probably taken to Africa during the travels of the many explorers of that continent. The earliest introductions were most certainly C. annuum and C. frutescens. The Spanish and Portuguese were instrumental in the introduction of chilies into western Africa and the Congo Basin (Miracle, 1967). It is also possible that Capsicum was introduced as a by-product of trading, missionary work, or colonial invasion.
Second, it is likely that various European botanical gardens were instrumental in introducing Capsicum into the colonies of Great Britian, the Netherlands, and France. This remains to be documented. However, it has also been suggested that Arab traders moved Capsicum into east Africa. The third, and last important exchange route was by way of the slave trade. It is suggested (Pickering, 1879;McClure, 1982) that ship captains returning to the west coast of Africa introduced many West Indian plants, including perhaps C. annuum, C. frutescens, and probably C. chinense.
The early history of the introduction of Capsicum into Africa is not well documented and is somewhat unclear, but by the 1800's reports of Capsicum species began to appear in the literature. Hooker (1849) reported C. annuum to be a common cultivated plant in Sierra Leone. Farquhar (1816) listed C. annuum and C. frutescens in his catalogue of exotic plants cultivated in Mauritius with the comment that C. frutescens was naturalized. Jardin (1891) mentioned the presence of wild C. annuum var. aviculare (= var. minimum) in Gabon with the vulgar name Ntogolo. Wherever Capsicum was introduced, it became popular as an easily grown cheap spice resource. Today, the market places of most African countries are brightened by quantities of peppers for sale.
Any consideration of pepper production in Africa poses certain difficulties. First and foremost is that reliable statistics are difficult to find and document. Second, peppers are grown for two different uses; first as a green vegetable crop and second as a condiment. In some countries the statistics for these two types of crops are merged while in others they are separate. Table 2 provides some data on area cultivated, yield, and production for green chilies in Africa. The three leading producers of these kinds of peppers are Nigeria, Egypt and Tunisia. However, such statistics fail to show how important red pepper is as a spice in native villages throughout Africa. This is illustrated in the case of Zaire where production of green chili has been fairly consistent since 1977 at 17 000 metric tons (FAO, 1980). The statistics for 1968 do not indicate that peppers were an important crop at that time (World Atlas of Agriculture). Neither source has anything to say about pepper production as a condiment, yet it is clear (Miracle, 1967) that spice peppers were widely grown in Zaire at this time but primarily for local consumption. He reports that spice peppers have been cultivated throughout Zaire by various tribal peoples including the northern Mongo, a forest dwelling people, who grow the crop intermixed with bananas-plantains, peanuts, tobacco, and various vegetables and that they also have been grown by  1969-71 1977 1978 1979 1969-71 1977 1978 1979 1969-71 1977 1978 1979 Africa 124  Another selected example that illustrates the potential for pepper production in Africa is the Malagasy Republic. Pepper production takes place along the south-eastern coast and amounted to 1 900 metric tons in 1965 (World Atlas of Agriculture, 1976). Virtually the entire crop is consumed locally and there is no export market. The crop represents both vegetable and spice peppers. Disease is a serious problem for the crop and may well limit its production. Nonetheless, Capsicum production is important and ranks among the top 15 crops for the country.
It is not the intent of this paper to consider production in Africa on a country by country basis. The cases of Zaire and the Malagasy Republic are offered here simply to illustrate several points. First, pepper production is of two types, vegetable and condiment. Second, the reporting statistics do not adequately indicate what kinds of peppers are being grown and for which of the two aforementioned purposes. Third, pepper production is, to a large extent, local and large acreages are seldom given over to growing the crop. Finally, Capsicum is rarely an important commercial crop anywhere in Africa.
Today, the most common type of peppers to be found in Africa belong to either the species C. annuum (vegetable) or C. frutescens (spice). Capsicum chinense is present in Africa, but is not nearly so widespread as the other two species which were almost certainly introduced into Africa in the 16th and 17th centuries. Capsicum annuum and C. frutescens seed is spread by birds. These species have become naturalized in southern Africa and most likely further north.