Talk about the class of filicopsida

Sporophyte of ferns has an underground rhizome. The rhizome carries on its backside adventitious roots. The large leaves or fronds are megaphylls. Ferns are the only vascular cryptogams to have well-developed megaphylls. Commonly fronds are compound; lamina is divided into leaflets, or pinnae, which are attached to the rachis, and extension of the leaf stalk, or petiole. Fronds emerge by Circinnate vernation, uncoiling process. The tips of young fern fronds are called fiddleheads. Sporangia are grouped in clusters called sori on the backside of sporophylls. The sorus usually has a protective layer termed indusium. Most of them are isosporic others are heterosporic. Gametophytes or prothallus, with flattened heart-shaped structures has many rhizoids.