Steiropteris polypodioides is endemic to Brazil (BA, MG, ES, RJ, SP and PR). It can be recognized by its lamina with truncate base, pinnae cuneate at bases, and linear sori. The most similar species is T. villosa, another Brazilian endemic from Bahia and Rio de Janeiro, which differs by having lots of hairs on its leaves.  Morphologically, they are unusual in Thelypteridaceae because of their linear sori.