Asplenium ceterach (syn. Ceterach officinarum) is a fern species commonly known as Rustyback. It is characterised by a short rhizome which gives rise to several green fronds that have a pinnated lamina with trichomes on the abaxial (lower) surface, but not the adaxial (upper) one. These trichomes (hairs) are orange-brown in colour, hence the name "rustyback". The petiole is shorter than the corpus of the leaf. This fern species has been used medicinally as a diuretic.