What is "ophioglossidae"

Ophioglossidae is a subclass of Equisetopsida in the sense used by Mark W. Chase and James L. Reveal in their 2009 article "A phylogenetic classification of the land plants to accompany APG III." This subclass comprises the ferns commonly known as whisk ferns, grape ferns, adder's-tongues and moonworts. It is equivalent to the class Psilotopsida in previous treatments, including Smith et al., 2006. Chase and Reveal originally listed the separate subclass, Psilotidae , in their 2009 paper, but Christenhusz et al., 2011, included both the Ophioglossales and Psilotales orders in the Ophioglossidae subclass.