This is one of the reasons that ferns are most commonly found in moist shady places. Some ferns have adapted to arid environments, but they still need wet periods to produce gametophytes and complete fertilization. The sporophyte generation in ferns and their allies is long-lived compared to the gametophyte. It is mostly larger and structurally more complex in that it has a vascular system of xylem and phloem, often associated structural supporting tissue and is mostly organized into highly specialized stems, leaves and roots. When mature and under appropriate conditions the spores are dispersed widely into the environment, and if they land in a suitable place germinate to create the next generation of gametophytes, completing the cycle.
Microspores produce the male antheridia and megaspores produce the female antheridia.
In addition to the sexual gametophyte-sporophyte life cycle, some of pteridophytes have developed various vegetative means of propagation to increase the extent and number of their population. This is advantageous where seasons are unreliable or the environment is otherwise not conducive to gametophyte production, and in some cases it may just be advantageous to generate numerous genetically identical individuals. A number of quite unrelated species produce vegetative buds or bulbils that are capable of producing roots and new plants. These bulbils are leaf derive structures and are produced in leaf axils or at various places on the leaf surface. Plants may chain along as successive bulbils take root, establish themselves and produce fronds and bulbils of their own.