Gymnocarpium - Woodsiaceae

Gymnocarpium robertianum (Hoffm.) Newman






Polypodium robertianum Hoffm.
Dryopteris robertiana (Hoffm.) C.Chr.
Polypodium calcareum Sm.
Dryopteris disjuncta (Rupr.) C.V.Morton

Common name

Limestone oak fern, Robert's oak fern, Northern oak fern.


Rhizome long-creeping, dark brown or black, forking. Fronds 40 x 15 cm, deciduous, monomorphic, blade/stipe ratio: 3:2 to 2:1. Stipe grooved, dull green, scaly at the base, soon falling. Lamina 2-pinnate-pinnatifid, triangular in outline, stiff, dull surface, very glandular, especially on the lower surface and the rhachis. Pinnae 9 to 12 pair, lowest pair similar in form (not size) to the next pair; pinnules lower basal pinnule of the lowest pinnae cut like adjacent pinnules , costae grooved above, continuous from rhachis to costae, margins entire to slightly crenate; veins free, simple or forked. Sori round, closer to the margin, on both edges of the segments; indusium absent.




Calcareous woodlands or swamps.

Distribution worldwide

Distribution in Africa

Algeria, Libya.

Growth form



  • Roux, J.P. (2009) Synopsis of the Lycopodiophyta and Pteridophyta of Africa, Madagascar and neighbouring islands. Strelitzia 23, South African National Biodiversity Institute, Pretoria. Page 219.
  • Stuart, T. (2004-) Hardy Fern Library. Published on the internet: Page 0. (Includes a picture).