The spores of the Lycopodium plant, called Lycopodium powder, or, often, dragon's breath, can be used in a variety of ways, including (but not limited to), naturopathic medicine (to stimulate an immune response), in the production of fireworks, to simulate lightning, and for magic.
Lycopodium powder can also be used in stage magic. A small amount of fine lycopodium powder can be sprinkled on a small spark or flame to produce a huge fireball that will burn and then disappear as quickly as it came.
Take a piece of flash paper (nitro-cellulose), a finger flash, or finger spark, and fill the finger flash with lycopodium and flash paper, and you can create fireballs to amaze your audience. (Most people jump back in a very satisfying way).
Coloured fireballs can be achieved easily:
Copper Sulfate Pentahydrate dissolved in water, mixed with the Lycopodium powder, and then dried, will create a green flame when ignited.
Potassium Nitrate dissolved in water, mixed with the Lycopodium powder, and then dried, will create a very blood red flame.
If you ever happen upon some Lycopodium powder, please keep in mind that the ball of flame produced in this effect is incredibly hot.