Cultivars
Several growers have attempted to selectively breed habanero plants to produce hotter, heavier, and larger peppers. Most habaneros rate between 200,000 and 300,000 Scoville units.
In 2004, researchers in Texas created a mild version of the habanero, but retained the aroma and flavor of the traditional pepper. The milder version was obtained by crossing the Yucatán habanero pepper with a heatless habanero from Bolivia over several generations. These mild habaneros were expected to be widely available in the future as of 2004.
Black habanero is an alternative name often used to describe the dark brown variety of habanero chilis (although they're slightly different, being slightly smaller and slightly more sphere-shaped). There have been cases where some types of seeds have been found, and they're thought to be over 7000 years old. It (the black habanero) has an exotic and unusual taste and is hotter than a regular habanero with a Scoville rating that ranges between 400,000 and 450,000 Scoville units. Small slivers used in cooking can have a dramatic effect on the overall dish. Gourmets delight in its fiery heat and unusual flavor. Black habaneros take considerably longer to grow than other habanero chili varieties. In a dried form, they can be preserved for long periods of time, and can be reconstituted in water then added to sauce mixes. Previously known as habanero negro, or by their Nahuatl name, they were translated into English by spice traders in the 19th century as "black habanero". The word "chocolate" was derived from the Nahuatl word, xocolātl, and was used in the description as well (as "chocolate habanero"), but it proved to be unpronounceable to the British traders, so it was simply named "black habanero".
Read more about this topic: Habanero Chili