[size=75]From Wikipedia, the free encyclopedia [/size]
The chili pepper, chilli pepper, or more simply just “chili”, is the fruit of the plants from the genus Capsicum, which are members of the nightshade family, Solanaceae. Even though chilis may be thought of as a vegetable, their culinary usage is generally as a spice, the part of the plant that is usually harvested is the fruit, and botany considers the plant a berry shrub. The latter description seems counter-intuitive to North Americans and Europeans, most of whom never see the perennial shrubs in their natural habitats. San Diego, California and the Florida peninsula may be the only locales in the United States of America where tropical perennials, such as chilis, frequently survive from one growing season to the next.
The name, which is spelled differently in many regions (chili, chile or chilli), comes from Nahuatl via the Spanish word chile. The term chili in most of the world refers exclusively to the smaller, hot types of capsicum. The mild larger types are called bell pepper in the USA, simply pepper in Britain, Canada and Ireland, capsicum in India and Australasia and paprika in many European countries.
Chili peppers and their various cultivars originate in the Americas; they are now grown around the world because they are widely used as spices or vegetables in cuisine, and as medicine.
Chili peppers have been a part of the human diet in the Americas since at least 7500 BC and perhaps earlier. There is archaeological evidence at sites located in southwestern Ecuador that chili peppers were already well domesticated more than 6000 years ago , and is one of the first cultivated crops in the Americas.
Chili peppers are thought to have been domesticated at least five times by prehistoric peoples in different parts of South and North America, from Peru in the south to Mexico in the north and parts of Colorado and New Mexico (Ancient Pueblo Peoples).
In the publication Svensk Botanisk Tidskrift (1995), Professor Hakon Hjelmqvist published an article on pre-Columbian chili peppers in Europe. In an archaeological dig in the block of St. Botulf in Lund, archaeologists claimed to have found a Capsicum frutescens in a layer dating to the 13th century. Hjelmqvist also claims that Capsicum was described by the Greek Therophrasteus (370-286 BC). He also mentions other antique sources. The Roman poet Martialis (around the 1st century) described “Pipervee crudum” (raw pepper) to be long and containing seeds. The description of the plants does not fit pepper (Piper nigrum), which does not grow well in European climates. 
Christopher Columbus was one of the first Europeans to encounter them (in the Caribbean), and called them “peppers” because of their similarity in taste (though not in appearance) with the Old World peppers of the Piper genus. Columbus was keen to propose that he had in fact opened a new direct nautical route to Asia, contrary to reality and the expert consensus of the time, and it has been speculated that he was therefore inclined to denote these new substances as “pepper” in order to associate them with the known Asian spice.
Chilis were cultivated around the globe after Columbus’ time.  Diego Álvarez Chanca, a physician on Columbus’ second voyage to the West Indies in 1493, brought the first chili peppers to Spain, and first wrote about their medicinal effects in 1494.