Botrychiaceae is a segregate family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of fern

Fern

A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...

s. The family includes the genera Botrychium (the moonworts), Botrypus (the rattlesnake fern), and Sceptridium

Sceptridium

Sceptridium is a genus of seedless vascular plants, closely allied to the genus Botrychium and also closely related to the genus Botrypus . They are commonly called the grape-ferns.These plants are small with fleshy roots, and reproduce by spores shed into the air...

 (the grape-ferns). Older fern classifications took a broad circumscription of Botrychium and included the genus in family Ophioglossaceae

Ophioglossaceae

Ophioglossaceae, the Adder's tongue family, is a family of ferns, currently thought to be most closely related to Psilotaceae, the two together comprising the class Psilotopsida as the sibling group to the rest of the ferns. The Ophioglossaceae is one of two groups of ferns traditionally known as...

.

The family is not recognized in the classification of Smith et al., who instead subsume the Botrychiaceae into the Ophioglossaceae

Ophioglossaceae

Ophioglossaceae, the Adder's tongue family, is a family of ferns, currently thought to be most closely related to Psilotaceae, the two together comprising the class Psilotopsida as the sibling group to the rest of the ferns. The Ophioglossaceae is one of two groups of ferns traditionally known as...

.