Ferns are plants that do not have flowers. They reproduce by tiny spores or sometimes can reproduce vegetatively, as exemplified by the walking fern.
Ferns are vascular plants that have specialized reproductive structures called gametophytes. They produce haploid gametes (eggs and sperm) by meiosis. The sperm are produced inside the archegonium, a special elongated sac with one opening at the top just below the archegoniophore, whereas eggs are generally produced in the gametophyte. The sperm released by meiosis swim to the archegonium and fertilization takes place.
The zygote develops into the diploid sporophyte, which remains attached to the gametophyte. The sporophyte produces structures called spores that grow into a haploid gametophyte. This cycle repeats itself as the sporophyte produces spores and as each spore grows into a gametophyte. The diploid phase provides two copies of the genetic material for sexual reproduction, while haploid phases provide single copies to be combined at fertilization during sexual reproduction.
Ferns are similar to flowering plants but lack flowers and seeds. In fact, both ferns and flowering plants have an alternation of generations: a spore-bearing generation (the gametophytes) and a seed-bearing generation (the sporophytes). The sporophyte generation is nonphotosynthetic in ferns, which may lead to their greater tolerance of shade.
Ferns first appear in the fossil record 360 million years ago in the Late Devonian. Fossilized remains of extinct fern-like plants from the late Silurian to early Carboniferous (about 425–320 million years ago) have been found. These appear as small, spore-bearing structures that resemble a fungus more than a seed plant.
One group of these fossils, called "progymnosperms" have been identified as a separate division of vascular plants. They grew in the wet soils of wetlands, but where they are found in good conditions for fossilization they appear to grow in fern-like clusters with upright stems and leaves similar to club mosses.
They also lack xylem vessels, indicating they did not transport water above ground. These fossils are still undated and so it is unknown when the transition from simple vascular plants to ferns took place.
Global ballfern leaves production
Between 1990 and 2015, global production of ballfern leaves increased from 2.3 million tonnes to 4.1 million tonnes. The majority of this increase was due to increases in production in Asia, which went from 1.6 million tonnes in 1990 to 3.2 million tonnes in 2015. The second-largest region of ballfern leaf production is Latin America, which produced 0.48 million tonnes in 1990 and 0.79 million tonnes in 2015. Africa is the third-largest producing region, with production increasing from 0.24 million tonnes in 1990 to 0.41 million tonnes in 2015.
The top five ballfern leaf producing countries are China, India, Brazil, Vietnam, and Indonesia. These five countries together produce approximately 80% of the world's ballfern leaves. China is by far the largest producer, with an output of 2.4 million tonnes in 2015. India is the second-largest producer, with 0.75 million tonnes produced in 2015. Brazil is the third-largest producer, with 0.48 million tonnes in 2015. Vietnam and Indonesia are the fourth- and fifth-largest producers, respectively, with outputs of 0.34 million tonnes and 0.33 million tonnes in 2015.
The global production of ballfern leaves is projected to continue to increase in the future as demand for the plant increases. The Asia-Pacific region is expected to see the largest increase in production, with an expected growth of 3.2% per year between 2015 and 2020. Latin America is projected to see a 2.7% annual growth in ballfern leaf production during the same time period. Africa is projected to see a 2.3% annual growth in production, while the rest of the world is expected to see a 1.7% annual growth.