Which of the following is not a fern?

Explanation

Tmesipteris is actually a genus of ferns belonging to the class Psilotopsida within the sub-division Psilophytina. Tmesipteris is a small genus of ferns that belongs to the class Psilotopsida. Psilotopsida is a class within the division Psilophyta, and this division includes ferns that are often considered primitive vascular plants. The class Psilotopsida includes not only Tmesipteris but also other genera like Psilotum. These ferns are unique because they lack true leaves and roots. Instead, they have small, scale-like appendages on their stems. Tmesipteris, like other members of Psilotopsida, exhibits simple vascular tissues and has a relatively simple overall structure compared to more advanced ferns.