Conifers, the largest group of gymnosperms, include pines, spruces, and firs. Most members of this group bear separate pollen cones and seed cones, usually on the same tree, and have simple evergreen leaves that are needle-like or scale-like. Conifers are found from the Arctic to the Antarctic circles, with a number of representatives in the tropics. While the exact number is unknown and disputed, it is believed there are about 500 native species.