Tên Khoa học: PsilotopsidaTên tiếng Anh: Tên tiếng Việt: Khuyết lá thôngTên khác:
Psilotopsida is a class of fern-like plants. As circumscribed by Smith et al. (2006) it contains one Psilotaceae family placed in orders Psilotales. The affinities of these two groups have long been unclear and a close relationship between them has only recently been confirmed through molecular systematic studies. Psilotopsida is the sister-group to all other ferns.