Tree ferns have complete trunks, but pteridophytes, which are vascular plants, contain leaves (sometimes referred to as fronds), roots, and occasionally real stems.
Ferns, horsetails, and club mosses are a few examples.
The longest fern species have fronds that may grow up to six meters long.
Evolution of Sorus in Pteridophytes:
Sorus evolved because it is a group of the sporangium.
In ferns, sori are formed on the abaxial and adaxial surfaces of the sporophylls.
Sometimes, sporangia either form marginal tassels over the surface of thin leaf divisions, as in Osmunda or are dispersed throughout the lower leaf surface to produce feet.