A hart's tongue fern (Asplenium scolopendrium) growing on a pile of mossy rocks. Watercolour. https://www.rawpixel.com/image/13967024/image-paper-plant-artFree Image from public domain licenseA fern frond, possibly of the male fern (Dryopteris filix-mas). Colour nature print, c. 1860. https://www.rawpixel.com/image/13960113/image-palm-tree-plantFree Image from public domain licenseFour fern fronds, one of a hart's tongue fern (Asplenium species). Chromolithograph after a nature print. https://www.rawpixel.com/image/13970772/image-cat-plant-medicineFree Image from public domain licenseThe male fern (Dryopteris filix-mas): fronds and part of rhizome. Colour nature print by A. Auer, c. 1853. https://www.rawpixel.com/image/13962052/image-plant-tree-artFree Image from public domain license