The spirits of flame are called salamanders.
“After it has passed through the sphere of the sylphs, the plant comes into the sphere of the elemental fire-spirits. These fire-spirits are the inhabitants of the warmth-light element. When the warmth of the earth is at its height, or is otherwise suitable, they gather the warmth together. Just as the sylphs gather up the light, so do the fire-spirits gather up the warmth and carry it into the blossoms of the plants."
Rudolf Steiner, The Plant-World and the Elemental Nature-Spirits, Lecture VII