Greek arachne - spider; referring to the web-like appearance of the young fronds.
Prickly Shield Fern
Medium to large terrestrial ferns. Rhizomes long-creeping or short and erect, covered with long, brown scales. Sterile and fertile fronds more or less similar. Fronds divided mostly 2-4 times, the final segments with toothed or bristled margins, evergreen; veins free. All grooves on upper stem surfaces continuous into the branches. Fertile fronds occasionally slightly smaller than sterile ones. Sori large, circular, in regular rows on either side of the midrib and away from the margin of each segment. Indusia kidney-shaped, attached by a central stalk, leathery.
Propagation: Spores or division of rhizome.
Recognition: Anadromous architecture. Basal branches often projecting downwards like Lastreopsis. Superficially similar to Rumohra but fronds generally smaller, rhizomes thinner and darker, and the indusia more kidney-shaped; also resembling Polystichum which, however, has a tufted habit and rarely has clearly continuous grooves on upper axis surfaces; Dryopteris rarely has the bristly saw-teeth.
Literature: Kurata (1962).
c.50-70 species E Asia to Australia (2 species) and New Zealand.
Created by: Val Stajsic
Updated by: Val Stajsic, May 2018