History

There is no conclusive proof that shows from where the chilli peper originated. Either South America or India seem the most likely, with most favouring either Central or South America. Many believe that Columbus was the first to bring them to Europe (from his second voyage) and called them peppers due to their similarity in taste and heat production to what we know today as black pepper. With the help of other explorers at the time their popularity spread like wild fire around the world and shortly afterwards they were being grown all over the world.

Increased migration, cheaper global travel, globalisation have all contributed towards bringing 'ethnic food' (whatever that may mean!) into the mainstream in westernised countries such as the UK. Many supermarkets now regularly many varieties of fresh chillies. Birds eye's, scotch bonnets, habenero's are all fairly easily found. If you can't find them in your supermarket then try you local indian/chinese/caribbean shop.

Species

There are five main varieties of chilli:

Capsicum annum:
These are the most commonly cultivated species and includes varieties such as the Bell pepper, Jalapeno & Cayenne. Their name is a bit misleading as infact they are perennials, and with abit of care ands attention can be overwintered.

Capsicum frutescens:
These are smaller bushy plants, the most popular variety of which is tabasco (the main ingredient of the famous sauce)! The pods are usually quite samll, prolific in number and grow 'upside down' or pointing upwards!

Capsicum chinense:
The name of these plants is derived from their supposed country of origination, China, though many believe they originated from South America. Their fruits are usually rounded in shape and more often than not very hot. The most common varieties are the Habenero and Scotch Bonnet.

Capsicum pubescens:
These are quite rare but can be easily be distinguished by their purple flowers. The pear shaped fruits are perfectly edible though they can be tricky to grow.

Capsicum baccatum:
These plants (also known as Ajis) tend to produce smaller berry like fruit but tend to be fast growing and fairly easy to grow.

How Hot?

There is an official heat scale to measure the heat in a chillie known as the Scoville scale, unsurprisingly named after it's inventor William L Scoville. The higher the Scoville Heat Units (SHU) the hotter the pepper. Here is a rough guide to some of the more popular varieties:

Bell Peppers 0
Jalapeno 5,000
Cayennes 40,000
Tabasco 20,000 > 50,000
Habanero 100,000 > 300,000
Red Savina 350,000 > 575,000
Naga Morrich 900,000
Anti bear Pepper spray 2,000,000