All seed plants produce 2 types of buds. The first is a leaf-bud, a form of vegetative reproduction repeating the foliage habit of the species. Some leaf buds have continuous growth, the outer adult leaves protecting the inner younger ones. The growth of these is checked only when weather conditions are against it. Most leaf buds have protective scales within which the bud can either lie dormant or form itself into a whole series of over-lapping young leaves ready to open out when they are needed or the season is appropriate.
The second kind of bud is sexually reproductive. The simplest of these is made when some of the inner bud scales become fertile by carrying pollen sacs or ovules. These open out into cones whose job is not to add growth to the plant but to produce new plant seeds from it. Once that job is done, the cones die and fall off the plant. In the biggest of the conifers it may take many years before the first seed cones are produced. Once the process has begun it may be continuous during the remaining life of the plant, as in many palms. It may also be a seasonal phenomenon, or it may end the life of a plant.
