Slash Pine needle and immature cone. The slash pine and Palmetto environment is very prone to fire and has therefore developed a symbiotic relationship with it. Slash pine cones are dependent upon fire in order to open and mature into viable seeds. Palmetto plants depend upon fire to trim dead leaf growth. Like all palms, they are a grass so their new growth emerges from the center of the plant and old dead growth sluffs off to the outside. Most palm have the wind to blow away this old growth. Palmettos grow close to the ground, so they can't depend upon the wind. Therefore, they depend upon fire to burn away old and dead growth.