- Psilotum nudum (L.) Beauvois
- Psilotum complanatum Sw.
The whisk ferns, traditionally thought not to be true ferns, are odd, "primitive" vascular plants that reproduce solely by spores, without seeds. Recent evidence has suggested that they may in fact be ferns that have lost a number of pteridophytic characteristics, but their status is still uncertain.
There are two species, as listed in the taxobox, with a hybrid between them known, Psilotum x intermedium W. H. Wagner.
The distribution of Psilotum is tropical and subtropical, in the New World, Asia, and the Pacific. The highest latitudes known are in South Carolina and southern Japan for P. nudum.