The fern plant pre-dates even the dinosaur. The leafy green plants occurred as far back as the Carboniferous period 300 million years ago, according to the Smithsonian Institute. Worldwide, approximately 10,500 species exist within 240 genera. Ferns are unique in the plant world because they do not reproduce by flowers. Instead their fronds produce reproductive spores.
The fronds of the fern vary in size. A few species attain fronds that measure up to 12 feet in length. The fern's frond has smaller leaves attached to a main stem. The smaller leaves are commonly called "pinnae."
Ferns occur around the world. They range in size from tiny plants that only attain a height of 2 to 3 inches all the way up to huge towering ferns that grow 30 feet in height. All ferns require the same basic growing requirements to thrive and reproduce. Ferns require adequate moisture and humidity for reproduction. The fern does not reproduce with pollen, as so many plants do, but it actually produces sperm that must swim to the spore for fertilization to take place on the frond.
On the underside of certain fern fronds are tiny dots known as "spores." The spores grow inside an outer coating known as "sporangia." Only a few fronds on a plant will have spores. Each spore can reproduce to make a new fern plant.
The spore on the underside of the frond has the capability of growing into a gametophyte. The gametophyte is both male and female. Each set of reproductive organs in the gametophyte is located close enough to each other to allow fertilization to take place when moisture lands on it. Once moist, the sperm will swim for the egg. Once fertilization takes place, a new fern is ready to begin.
If the fern's fronds begin to dry at the tips and curl, the fern is not receiving enough humidity. To maintain the fern's lush, green fronds raise the humidity in the room by placing a humidifier near the plant or moving it into a bathroom where it can receive daily humidity. Daily misting of the fern fronds should be avoided because it can cause foliar leave spot diseases to occur on the leaves, according to the University of Minnesota.