The chili pepper is the fruit of plants from the genus Capsicum, members of the nightshade family, Solanaceae. The genus Capsicum contains 5 domesticated species and 22 wild species.
Wild pepper species of capsicum are the ancestors of all domesticated species which contain over 3000 varieties. All species of wild capsicums have certain common characteristics: small, hot, red fruits that may be round, elongated or conical and are attached to the plant in an erect position. The seeds of these fruits are dispersed by birds that are not affected by the heat.
When humans began to cultivate the capsicum plant they selected seeds from those fruits that where difficult to remove from the calyx so that birds could not pluck them. Pendent fruits became more desirable, and today most domesticated capsicums have pendent fruits instead of erect. Each time larger fruits where selected, the size and weight increased, which caused the capsicums to become pendent.
Listed below are the 5 domesticated species.
Capsicum annuum (AN-yoo-um):
Includes many common varieties such as Bell peppers, wax, Cayenne, Jalapeños, and the Chiltepin. Although the species name annuum means “annual” the plant is not an annual and in the absence of winter frosts can survive several seasons and grow into a large perennial shrub. The single flowers are an off-white (sometimes purplish) color while the stem is densely branched and up to 60 centimeters (24 in) tall. The fruit is a berry and may be green, yellow or red when ripe. While the species can tolerate most climates, C. annuum is especially productive in warm and dry climates.
Capsicum baccatum (bah-COT-tum or bah-KAY-tum):
Includes South American Aji peppers, Peppadew, Lemon drop, Bishop’s crown, and Brazilian Starfish. The wild baccatum species (C. baccatum var. pendulum) is the domesticated pepper of choice of Bolivia, Ecuador, Peru and Chile. The fruit pods of the baccatum species have been cultivated into a wide variety of shapes and sizes, unlike other capsicum species, which tend to have a characteristic shape. The pods typically hang down and can have a citrus or fruity flavor.
Capsicum chinense (chi-NEN-see):
Includes the hottest peppers such as the Naga, Habanero, Datil and Scotch Bonnet. C. chinense is native to Central America, the Yucatan region, and the Caribbean islands. In warm climates such as these, it is a perennial and can last for several years. Within C. chinense, the appearance and characteristics of the plants can vary greatly. Varieties such as the well-known habaneros grow to form small, compact perennial bushes. The flowers, as with most Capsicum species, are small and white with five petals. When it forms, the fruit varies greatly in color and shape, with red, orange, and yellow being the most common, but colors such as brown are also known. Another similarity with other species would be shallow roots, which are very common.
Capsicum frutescens (froo-TESS-enz):
Includes Malagueta, Tabasco and Thai peppers, Piri Piri, and Malawian Kambuzii. The Capsicum frutescens species likely originated in South or Central America. It spread quickly throughout the tropical and subtropical regions in this area and still grows wild today. Capsicum frutescens is currently native to the majority of Central America as well as Northern and Western South America. It is believed that C. frutescens is the ancestor to the C. chinense species. Pepper cultivars in Capsicum frutescens can be annual or short-lived perennial plants. Flowers are white with a greenish white or greenish yellow corolla. The plants’ berries typically grow erect. They are usually very small and hot. Fruit typically grows a pale yellow and matures to a bright red, but can also be other colors. C. frutescens has a smaller variety of shapes compared to other Capsicum species, likely because of the lack of human selection.
Capsicum pubescens (pew-BES-enz):
Includes the South American Rocoto peppers. The species name, pubescens, means hairy, which refers to the hairy leaves of this pepper. The hairiness of the leaves, along with the black seeds, distinguish this species from others. As they reach a relatively advanced age and the roots lignify quickly, sometimes they are called tree chili. They grow into four-meter woody plants relatively quickly, and live up to 15 years, which gives them, especially with age, an almost tree-like appearance. Of all the domesticated species of peppers, this is the least widespread and systematically furthest away from all others. It is reproductively isolated from other species of the genus Capsicum. A very notable feature of this species is its ability to withstand cooler temperatures than other cultivated pepper plants, but cannot withstand frost.
Capsicum frutescens is sometimes distinguished as a species separate from Capsicum annuum, while some botanists consider them to be conspecific.