Selaginella apoda, commonly known as meadow spike-moss, is a lycophyte native to much of the eastern United States and parts of northeastern Mexico. It is found primarily in damp soils in habitats such as swamps, wet fields, open woods and along stream banks. A lowland plant, it has only been recorded at elevations below 100 metres. It is closely related to Selaginella eclipes and S. ludoviciana, both of which it has been reported to form hybrids with. This group is characterised by relatively flat strobili and large megasporophylls which occur in the same plane as the lateral leaves.