Ferns range in size from just a few inches to 25 meters in height. The leaves of a fern are known as fronds . Spores form in sacs called sporangia on the under side of the fronds. The species name gives you a hint. It is a multicellular structure containing an embryo plant and its food.
Seeds can survive long periods of inactivity between their formation and activation.
Today, seed plants are the most successful plants on Earth. There are about 700 species of gymnosperms. About 90,000 species are known. About 185,000 species are known. Monocots and dicots are easily distinguished by their physical characteristics.