With more than 20,000 different types of trees, seeds obviously come in many varieties. Deciduous trees, also known as broadleaved trees, have the noticeable characteristic of dropping leaves in autumn, and produce flowers and fruit that help spread the seeds. Coniferous trees produce cones containing the seeds, instead of flowers, and keep the needles all year round. Both rely on winds and animals to help scatter the seeds for reseeding the population.
Gymnosperm Seed Cones
Gymnosperms are non-flowering trees that produce seeds considered naked, yet originate from coniferous trees. An example of this type of seed is a pine cone, or yew seeds. This style is comparable to other coniferous trees like the Douglas fir, that hide just one seed under each scale of their papery cones.
Angiosperm trees have ovaries that produce seeds and are of the deciduous variety. These trees normally produce multiple seeds that are contained in a fruit, like the typical apple or pear trees. Trees that produce fruit harbouring a single seed, or pit, like a plum or cherry tree, also belong to the angiosperm classification of tree seeds, as they flower and have ovaries.
Angiosperm Wings, Pods and Husks
Angiosperm seeds also have a classification of seeds that are encased in wings, pods or husks, like the twirling helicopters associated with maple trees. Trees that produce pods are elms and ash trees and generally have pods covering the seeds located at the base of the wings that help propel and disperse them. Another categorisation within the angiosperm seed are those that are encased in husks, or hard shelled structures that require breaking apart to germinate. Walnut trees are a good example of this type of tree seed.