Capsicum refers to a wide variety of tropical pepper plants with the genus of the same name. The name is perhaps derived from the Latin "capsa," or box for the pod-like fruit. Capsicum also refers to the fruit produced by any of these plants, in particular the dried fruits that are typically used in medicine and as condiments.

Common names for these plants are cayenne, cayenne pepper, chili pepper, paprika, peppers, pimiento, red pepper, sweet pepper, aji dulce, Hungarian pepper, and Mexican pepper.

The original habitat is unknown but the plants are probably native to the tropics. They are found in many places, including China, Dominican Republic, Haiti, Hawaii, Europe, India, Iraq, Malaya, Mexico, Philippines, Samoa, Spain, Tonga and the U.S.

Cayenne or Capsicum takes its name from the Greek, 'to bite,' a reference to the hot pungent properties of the fruits and seeds. The plant was described by Linnaeus as C. frutescens proper. Introduced from India into Britain in 1548, the plant was already being cultivated. It appeared in 1771 in Miller's Garden Dictionary.

The fruits contain 0.1 - 1.5% capsaicin, a substance which stimulates the circulation and alters temperature regulation. Applied topically, capsaicin desensitizes nerve endings and makes a good local anesthetic. The seed contains capsicidins, which are thought to have antibiotic properties.

The dried fruit has no narcotic effect but as a powerful local stimulant, it is effective in dilating blood vessels and relieving chronic congestion. Due to its high vitamin C content, it is said to be good at warding off disease.

Used externally as a pack or liniment, it stimulates circulation, aids the removal of waste products, and increases the flow of nutrients to the tissues. It is also said to relieve muscle spasms, bursitis, shingles, and diabetic neuropathy. Powdered and placed inside socks, it is a traditional remedy for cold feet.

The fruit is also said to have antihemorrhoidal, antiseptic, and antirheutmatic properties and to be good for digestive, sinus, and stomach conditions. In the tropics, they also serve as food preservatives.

The fruit can be used raw or cooked. It is normally used as a flavoring. The fruit can also be dried and ground into a powder for use as a flavoring. The seeds are also dried, ground and used as a pepper and the leaves can be cooked as a potherb.

There are no known hazards associated with the species, but some plants in this family produce toxins in their leaves while the sap of the plant can cause skin to blister.