1) Family psilotaceae 2) Fern family 
Psilotaceae is a family of fern-like plants (in order Psilotales) consisting of two genera, Psilotum and Tmesipteris. The two genera are very different and in the past Tmesipteris has been placed in its own family, Tmesipteridaceae, but most classifications continue to place it in Psilotaceae. The relationships of Psilotaceae have been unclear, in...
[n] - small family of lower ferns having nearly naked stems and minute scalelike leaves
family Psilotaceae noun small family of lower ferns having nearly naked stems and minute scalelike leaves