Cryptogramma

Petite Rollfarn ( Cryptogramma stelleri )

The Roll ferns ( Cryptogramma ) is a genus in the family of Saumfarngewächse ( Pteridaceae ) and belong to the genuine ferns ( Polypodiopsida ).

Features

The Roll ferns are perennials with a creeping rhizome and tubular or reticular vascular system. The leaves are strikingly different, depending on whether they are fertile or sterile. The sori are submarginal, they are schleierlos and later form a single sorus at the end of the wires. The spores are tetrahedral.

Systematics and distribution

There are about nine species of the genus Cryptogramma R. Br Their distribution is limited almost to Europe, Asia and North America, southern South America, there are only a few isolated occurrences. In Europe there are only two ways:

• Krauser Rollfarn ( Cryptogramma crispa (L.) R.Br. ex Hook; Syn. Allosorus crispus (L.) Bernh. ), With three times pinnate leaves
• Petite Rollfarn ( Cryptogramma stelleri (SG Gmel. ) Prantl ), with twice pinnate leaves, occurs in North America and reached East Asia from Russia just in Europe

Other types are (selection):

• American Rollfarn ( Cryptogramma acrostichoides R.Br. ), is found in East Asia ( Kamchatka ) and North America, south to Mexico
• Cryptogramma brunoniana Wall. ex Hook. & Grev. , Occurs in eastern Asia and western North America
• Cryptogramma raddeana Fomin, occurs in East Asia
• Cryptogramma sitchensis ( Rupr. ) T. Moore, is found in North America