Ferns are ancient plants thriving in dim forests and riverbanks for over 300 million years, predating dinosaurs, and existing alongside clubmosses and horsetails in primordial swamps.

Unraveling the origin of ferns intertwines with Earth's oldest history, potentially revealing the ultimate tale of our planet. Thus, amid the vast stream of time, continuous learning and exploration of various plant species' human history may someday unveil the true nature of our inhabited Earth.

Ferns are the earliest spore-producing plants on Earth. Mostly herbaceous with some being woody, they serve as a link in plant evolution from lower to higher forms. In ancient times, tree ferns and horsetails stood tall, crucial contributors to coal formation.

Modern surviving ferns, except for the sole surviving tree fern, the Cyathea, are herbaceous. Ferns lack flowers, fruits, or seeds, reproducing through spores. They are broadly categorized as the classes of ferns: Equisetopsida (horsetails), Psilotopsida (whisk ferns), Marattiopsida (mattoid ferns), and Polypodiopsida (true ferns).

The so-called "tree ferns," scientifically known as Cyathea, are remnants of ancient tree ferns, contributing significantly to coal and petroleum formation, symbolizing the enigmatic "Cyatheales" clan in an undetermined lineage.

In the evolution of life, ferns emerge as a marvel, being the earliest land colonizers, surviving for over 300 million years. They were the primary sustenance for dinosaurs, outlasting their extinction. Ferns precede gymnosperms; many of these now relic species thrive while gymnosperms diminish. Ferns, the ancestors of angiosperms, still thrive despite today's blooming fields of flowers.

The life cycle of ferns comprises two phases: the sporophyte and the gametophyte stages. The familiar fronds seen in forests and gardens represent the sporophyte stage. Sporting an underground stem (rhizome) covered with delicate scales, ferns' sporophytes are perennials capable of surviving for several years.

In regions with distinct seasons, their leaves wither every autumn, only for new ones to sprout from the underground rhizome the following spring. Woodland ferns like the shield fern and lady fern wilt in winter, but their dried leaves safeguard the growing point (rhizome), enabling them to survive the harshest climates.

Some ferns produce bulbils resembling light bulbs on the underside of their small leaves. Once matured, these bulbils drop to the ground, sprouting into new plants. The sword fern grows new plants from its spear-like leaf tips. When the new plant's leaves arch and touch the soil, they take root, allowing the plant to "walk" forward in the soil.

Most ferns carry spores on their fronds. Spores develop in sporangia, clustered in sporangia groups beneath the lower leaf surface. As they mature, these sporangia change color, gradually turning brown or red.

In fact, due to their ancient evolutionary status and uniqueness, ferns hold significant and distinct value in culinary, medicinal, and landscaping fields, yet there's limited foundational research in this domain. For instance, ferns are rich in amino acids and low in oil content, constituting a remarkably healthy vegetable category.

Nearly all ferns are rich in flavonoids and possess almost no highly toxic alkaloids, promising potential health food or medicinal applications. Numerous ferns can synthesize natural molting hormones, serving as promising candidates in cosmetic developments.