Fern sports are plants that show marked change from the normal type or parent stock as a result of mutation. The term Morphotype is also used for any of a group of different types of individuals of the same species in a population. Fern fronds in sports are typically altered in several ways, such as the frond apex divided and pinnae similarly duplicated.[1]
Soft Shield Fern Polystichum setiferum, Lady Fern Athyrium filix-femina[2] and Hart's Tongue Fern Asplenium scolopendrium are known to have around three hundred varieties or sports.[3] Scaly Male Fern Dryopteris affinis and Male Fern Dryopteris filix-mas have a number of commercially available and naturally occurring sports or subspecies. Examples are D. affinis polydactyla Dadds, A. filix-femina plumosum, A. filix-femina corymbiferum, and D. filix-mas Barnesii [4]
The frond of a sport may be branched at the tip and at the tips of the pinna, the colour may vary, and variegation may occur; fronds generally remain bilaterally symmetrical. Ferns sports remain normal in certain respects, such as viability with sori and indusia appearing normal. The frond stipe may be a different colour.[5]
Ferns sports particularly suffered during the Victorian-era Pteridomania ('Fern-Fever') craze, when over collecting of fern species included over collecting unusual fern varieties.[3]