Thyrsopteris

Thyrsopteris elegans

Thyrsopteris elegans is a representative of tree ferns ( Cyatheales ). The species is the only one of the genus Thyrsopteris and Thyrsopteridaceae family. It just comes down to the Juan Fernández Islands off the coast of Chile.

Features

The rhizomes are ascending or erect and have a Solenostele. They are offshoots and are occupied with stiff, multicellular hairs. The leaves are 2 to 3.5 m long, pinnate three -to five- fold and partially dimorphisch: the sori are often limited to the proximal blade segments. The blade axes are grooved at the top. The nerve end freely. The sori are terminal to the nerves, external and internal indusia are fused and form asymmetric, cup-shaped structures. Each sorus is in its own columnar - club-shaped receptaculum. The sporangia have opaque Anuli. The spores are globose to tetrahedrally and distinct edges.

The chromosome number is x = about 78

Dissemination

The species is endemic to the Juan Fernández Islands.

System

The exact systematic position of the species is unclear, but is clearly related to the tree ferns.

Documents

• Alan R. Smith, Kathleen M. Pryer, Eric Schuettpelz, Petra coral, Harald Schneider, Paul G. Wolf: A classification for extant ferns. In: taxon. Volume 55, No. 3, 2006, ISSN 0040-0262, pp. 705-731, Abstract, PDF file.