Botrychium simplex is a small fern, variable in size, but the blades often less than 5 (7) cm tall. The blades are usually less than fully divided and small plants may have only 3 segments. Very small plants may appear similar to Botrychium mormo which has fleshier leaves and stalk.

B. simplex ranges from Minnesota and Iowa through the northeastern U.S. and adjacent Canada, and south as far as North Carolina in the east. It is also present in the western U.S. and Canada, but is absent from the Great Plains area. In Wisconsin it is widely distributed, but most records are from the northern half. Habitats include old fields, clearings and bracken grassland, but it is also found in swamps and occasionally in mesic forest. It is probably more common than the voucher record indicates.