Deer Fern, also known as Blechnum spicant by its Latin name, is one of many ferns that can be found in Seattle's natural areas. Ferns are a group of plants that do not have flowers. They are an ancient plant and many a fern has been preserved in a fossilized form. You can buy fossils of fern leaves easily online or at your local museum. Ancient ferns have been turned into our fossil fuels. Because it took millions of years to create, fossil fuels can not be renewed.

The leaves of the ferns are called fronds. Because ferns do not flower, they also do not have seeds and fruits, but rather have spores. You can see the spores on the back of the fronds. Deer Ferns have two types of fronds. Both types grow together out of common root clumps. The sterile fronds usually lie relatively flat to the ground and do not have spores on their back side. Fertile fronds, which have widely spaced narrower leaves on their fronds, are taller and more erect than the sterile fronds. The back sides are covered with spores. To see and understand the life cycle of a fern, check out this tutorial web page: http://www.jburroughs.org/science/resources/fern/Ferntitle.html

During the Carboniferous Period (360 to 286 million years ago), ferns were the most common type of plant and could grow into trees. As the trees and plants died, they sank to the bottom of the swamps in which they grew. They formed layers of a spongy material called peat. Over many hundreds of years, the peat was covered by sand and clay and other minerals, which turned into a type of rock called sedimentary rock.

More and more rock piled on top of more rock, and it weighed more and more. The peat was squeezed until it eventually turned into coal, oil or petroleum, and natural gas. On the microscopic level, coal is made up of organic grains called macerals. One type of maceral are composed of hydrogen-rich hydrocarbons derived from spores, pollens, and resins in the original plant material. Other macerals are composed of wood, bark, and roots, and contain less hydrogen. When we burn the hydrocarbons, they produce energy, but they also produce carbon dioxide. And it is the build up of carbon dioxide in the atmosphere which is causing global warming.

So next time you look at a fern, think of how much energy you are using to heat and light your home and how much carbon dioxide is being emitted into the air that was originally a fern.