This is widespread in southeastern states, especially in somewhat disturbed wooded sites on seasonally damp soils. Chromosome numbers in the genus tend to be unusually high. FNA 2 states: "The chromosome number of O . vulgatum in India and Europe has been reported as 2n = 480, and that may be the number of most North America populations [as pycnostichum], which are small-spored. In the Appalachians, however, a distinctive large-spored form has a chromosome number of 2n = ca. 1320."