Lingering Flames(Complete Mage, p. 110)
Level: Sorcerer 6, Wizard 6, Wu Jen 6 (fire),
Components: V, S, M,
Casting Time: 1 standard action
Range: Medium (100 ft. + 10 ft./level)
Area: 20-ft.-radius spread
Duration: 3 rounds
Saving Throw: Reflex half
Spell Resistance: Yes
A burst of flame erupts before you, raising the temperature of the area to scorching levels.
This spell functions like fireball, except that the area remains filled with fire for the spell's entire duration. Any creature within or entering the area takes 1d6 points of fire damage per caster level (maximum 15d6); a successful Reflex save halves this damage.
Material Component: A pinch of sulfur and a length of copper wire.