"Maduro" is a Spanish adjective meaning "ripe". By the loosest definition, a wrapper leaf is a maduro if it's dark enough. Maduro is really a shade of tobacco, not a wrapper type. But it's being used more and more as a wrapper type so I felt inclined to include it.
Maduros are generally thought of as either Broadleaf or of Brazilian origin. But take the Padron Natural and Maduro line for example and the only difference between the two is how long the leaves are exposed to the sun and the curing process. Maduros are usually stalk-cut instead of primed (layers of leaves at a time). The plants are cut at the base and allowed to wilt in the sun for a few hours to make them easier to handle. Quality Maduros are cured over a long period of time, often up to 5 years.
Due to the wrapper's popularity, many have found shortcuts to getting a dark wrapper color. One method is painting the wrappers or dipping them in dye (I swear you can write on the wall with the head of a CAO MX2). Another is cooking the leaf using a device similar to a stovetop espresso coffee maker. Here's a great article on Maduro cigars.
- Brazilian Maduro - see sections on Mata Fina or Arapiraca wrappers.
- Connecticut Broadleaf - see section on CBL.
- Costa Rican Maduro - very earthy, kind of like that weird flavor you get with a Mexican wrapper, but a little different. Try the Carlos Torano Reserva Selecta Maduro and the Bucanero Canon Cubano Maduro.
- Mexican Maduro - uses the San Andres Negro strain for this wrapper.
- Nicaraguan Maduro - My favorite maduro wrapper, the Nicaraguan version will more likely have more spice and earth than sweet, but the sweetness rounds and calms the strength and oomph of Nicaraguan tobacco. The best example is any Padron.