View the Seeds of Life site for illustrations and information about fruits and seeds. Seeds germinate, and the embryo grows into the next gemeration sporophyte. Coconut fruit containing the seed you usually buy at the store. Image from W.H. Freeman and Sinauer Associates, used by permission. Often some species, such as many orchids, are more frequently propagated vegetatively than via seeds.
Tubers are fleshy underground stems, as in the Irish potato.
Leaflets are sections of leaf will develop roots and drop off the plant, effectively cloning the plant. Runners are shoots running along or over the surface of the ground that will sprout a plantlet, which upon settling to the ground develop into a new independant plant. Some excellent photographs of fruits and seeds as well as a set of links to related topics. The Naked Seeds of Pinus Text and nice graphics on the life cycle of pines. A collection of images.