Conifers are the largest group of gymnosperms. They are monoecious, producing megastrobili (seed cones) and microstrobili (pollen cones) on the same plant. They generally produce small needle- or scal...Conifers are the largest group of gymnosperms. They are monoecious, producing megastrobili (seed cones) and microstrobili (pollen cones) on the same plant. They generally produce small needle- or scale-like leaves with a thick, waxy cuticle.