Chinese Brake, Ladder Brake – Exotic

Close but differs because terminal pinnae are not sharply  toothed but the pinnae are lightly serrated along the edge. terminal pinna 2 times length of closest pinnae this differs on different descriptions, vascular tissue perfect C shape single

not Blechnum serrulatum (Swamp Fern) and Thylepteris serrata sori cover whole bottom

            

found in a pot of Sanseveria dug from the back.