The plant is a herbaceous annual, with a densely branched stem. The plant reaches 0.5–1.5 m (20–60 in). Single white flowers bear the fruit which is green when unripe, changing principally to red, although some varieties may ripen to other colours including brown and purple.
While the species can tolerate most climates, they are especially productive in warm and dry climates.
Due to this climate tolerance, and the variety of flavors available, this New World plant spread across the world, possibly faster than any other crop.
In British English, the sweet varieties are called peppers and the hot varieties chillies, whereas in Australian and Indian English the name capsicum is commonly used for bell peppers exclusively and chilli is often used to encompass the hotter varieties.
Common varieties include:
Hot peppers are used in medicine as well as food in Africa.
John Lindley (1799-1865) wrote in his 'Flora Medica' (1838) about Capsicum annuum, page 509: 'It is employed in medicine, in combination with Cinchona in intermittent and lethargic affections, and also in atonic gout, dyspepsia accompanied by flatulence, tympanitis, paralysis etc. Its most valuable application appears however to be in cynanche maligna and scarlatina maligna, used either as a gargle or administered internally.'