The thick, leathery fronds are pinnately divided into rounded lobes and form clumps. The back of the frond is covered in rusty-coloured scales. Frond length up to 20cm.
Found growing in the crevices of lime-rich stone walls or rocks, especially in the mortar of old walls. It can withstand drought and will curl itself up. A native species which is widespread but common only in the south-west of England, west Wales and Ireland.
Photographs of Rustyback (Asplenium ceterach), taken August 2015, Torquay, Devon. © Pete Hillman 2015. Camera used Nikon D3200, with Sigma 105mm macro lens.