When examining a cone closely you would notice that they are quite intricate and some could be full of seeds. There are two different kinds of plants that have seeds: flowering plants have seeds that are inside of a fruit, such as an apple and berries, while some non-flowering plants have seeds that are not inside of a fruit, for example pine cones.
A cone is neither a fruit nor a seed. What most of us call a pine cone is really a cluster of modified woody scales that are tightly packed together to protect the developing conifer seeds inside. Each species of conifers has male and female cones. Most of the male cones are found on the lower branches, while many of the female cones are found on the upper branches. The male cones appear as dust-coated fingers in late spring, and the female cones are tiny, pinkish structures that appear at the ends of new growth. The male cones have elongated structures, with yellow pollen that floats away on the wind, covering sidewalks, decks and cars.
Luckily, some of that pollen also lands on the female nubs, which will develop into mature pinecones full of little winged seeds.
The male cones, which do not grow very large, are rather inconspicuous and are shed from the tree soon after releasing their pollen. After being pollinated, the female cones continue growing until autumn.
Depending on the tree species, female cones can be as small as one quarter of an inch and as large as over two feet.
Most conifers produce male and female cones on the same tree but some, such as the yews and junipers, appear on separate trees, with their cones resembling small fruits more than cones.
In most pine trees, it could take 18 to 24 months for the female cones to reach maturity. When the seeds inside a female cone reach maturity, the cone changes color from green to brown, and the scales separate to expose the seeds that will soon fall out of the cones. For some species, such as pitch pine, their cones will remain closed on the tree for years without releasing seeds until exposed to a temperature of over 130 degrees Fahrenheit, which usually occurs after a forest fire has burned the leaf debris on the forest floor, making it suitable for seedlings to germinate. White pine cones open and drop their seeds late in their second summer and then drop off the tree; white spruce cones open and fall during their first winter; black spruce cones mature in one year but can remain on the tree for several years, while releasing a few seeds each year and after balsam fir cones mature, the scales and a few seeds will flake off over a period of several days to weeks, leaving bare cores on the tree. (This particular dispersal method is a welcome invitation to red-breasted nuthatches, which can easily extract the balsam fir seeds.)
After ripening, pine cones are affected by moisture. The cones will open when dry and close when becoming wet. A pine cone will go through many cycles of opening and closing during its life span, even after seed dispersal is complete. This process occurs with older cones while attached to branches and even after the older cones have fallen to the forest floor. The condition of a pine cone lying on the ground is an indication of the forest floor’s moisture content, which is an important indication of wildfire risk. Closed cones lying on the forest floor indicate the forest floor is dry.
Conifer seeds are dispersed by both wind and animals. The wind dispersed seeds are usually small, with a prominent wing that enables the seeds to be carried away from the parent tree. Animal dispersed seeds, which are larger, are not immediately consumed but are carried away from the parent tree and hidden. If the bird or animal does not recover these seeds they will germinate.
Even after the cones fall to the ground the cones are used by insects.
If you take a cone and tap it on a piece of white paper, you will be surprised at what you see.