A bright flame, equal in brightness to a torch, springs forth from the caster's palm when he casts a produce flame spell. The flame does not harm the caster, but it is hot and it causes the combustion of flammable materials (paper, cloth, dry wood, oil, etc.). The caster is capable of hurling the magical flame as a missile, with a range of 40 yards (considered short range). The flame flashes on impact, igniting combustibles within a 3-foot diameter of its center of impact, and then it goes out. A creature struck by the flame suffers 1d4+1 points of damage and, if combustion occurs, must spend a round extinguishing the fire or suffer additional damage assigned by the DM until the fire is extinguished. A miss is resolved as a grenadelike missile. If any duration remains to the spell, another flame immediately appears in the caster's hand. The caster can hurl a maximum of one flame per level, but no more than one flame per round.
The caster can snuff out magical flame any time he desires, but fire caused by the flame cannot be so extinguished. This spell does not function under water.
Notes: Common for druids (PHB).
Sage Advice
Dragon Magazine 148:
Q. How long does a produce flame spell last? How many flames can the caster hurl?
A. Produce flame lasts one round per caster level. The caster can throw a maximum of one flame per level, but no more than one flame per round.