The Humming Dragon, scientifically known as Draco Minimus Floralis, was the smallest of all dragons, measuring about 3 to 4 inches from nose to tip to tail. It was capable of breathing fire, which it would produce involuntarily if stroked.
The humming dragon became much prized by gauchos during the early 19 century as "Field Matches" because of it's usefulness in lighting campfires.
Potentially because of it's overuse by gauchos, none have been spotted in the wild since 1820, so it is assumed to be an extinct species of dragon. However, this is only an assumption.