The five major domestic cultivated pepper species (genus Capsicum) are C. Annuum, C. Chinense, C. Baccatum, C. Frutescens and C. Pubescens – and within those species one have the ability to cross and generate Interspecific Hybrids.

Capsicum Annuum (AN-yoo-um)
Includes many common varieties such as Bell peppers, Cayenne, and Jalapeños. 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 size-able perennial shrub, with a densely branched stem. The plant reaches 0.5–1.5 m. Single white flowers develop into the fruit, which is typically green when unripe, but may lack chlorophyll causing a white color. Ripening fruits usually change to red, although some varieties may ripen to yellow, orange, peach, brown, or purple. The species are grown in temperate climates as an annual, but they are especially productive in warm and dry climates.

Capsicum Baccatum (bah-COT-tum or bah-KAY-tum)
When speaking about Baccatums, a majority of the time we are really talking about C. Baccatum var. pendulum. These are Capsicum Baccatums with fruits that hang down (pendant) instead of being upright, and include South American Aji peppers, Peppadew, Lemon drop, Bishop’s Crown, and Brazilian Starfish. The 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. These have a distinctive, fruity flavor, and are commonly ground into colourful powders for use in cooking, each identified by its colour.

Capsicum Chinese (chi-NEN-see)
C. Chinense includes some of 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 develops, 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 Fructescens (froo-TESS-enz)
From Capsicum Annuum, while some botanists consider them to be a member of the same species. It includes Malagueta, Tabasco, Thai peppers, Piri Piri, and Malawian Kambuzii. Capsicum Frutescens is currently native to the majority of Central America as well as Northern and Western South America. 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 tiny 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)
The species name, Pubescens, means hairy, which refers to the hairy leaves of this pepper plant. 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 (become woody by the deposition of lignin), sometimes they are called tree chili. They grow into four-meter woody plants relatively quickly and live up to 15 years. As they age, they can take on an almost tree-like appearance. Of all the domesticated species of peppers, this is the least widespread and systematically furthest away from all others. A very notable feature of this species is its ability to withstand cooler temperatures than other cultivated pepper plants, but cannot withstand frost.
Article content by cayennediane.com and wikipedia.org