The Ferns (Filicopsida) of the British Isles
The Ferns (Filicopsida) of the British Isles | |
“Jersey Fern”.
Gymnogramma leptophylla (L.) Desv., Grammitis leptophylla (L.) Sw.).
Sporophyte. Plants very shortly rhizomatous (the plants annual, although the subterranean prothalli are perennial). The rhizomes when young, bearing scales (with a few narrow scales). Plants bearing markedly different fertile and sterile leaves (the outer, sterile leaves tend to be shorter, are less divided and have broader segments than the inner, fertile leaves).
Leaves aggregated terminally (in a few-leaved crown); to 5–15 cm long (the outer, sterile ones shorter); dying in the autumn; complexly divided; once pinnate, with conspicuously divided pinnae, or bipinnate with conspicuously divided pinnules to tripinnate with undivided ultimate pinnules (the primary pinnae pinnately lobed to pinnatifid or (in sterile leaves) almost palmatifid, with the ultimate segments themselves lobed). The petioles shorter than the blade to longer than the blade; vascularised via a single strand. Leaf blades ‘herbaceous’ (but thin). The venation of the lamina open.
The sporangia superficial; protected; initially aggregated in sori. The sori elongated (linear, running along the ultimate veins); becoming confluent when mature; naked and neither indusiate nor pseudo-indusiate (and the leaf margin flat). Paraphyses absent. The mature spores trilete; without a perispore.
Distribution and habitat. On damp, shady hedgebanks. Channel Isles: frequent in Jersey, and known from one location in Guernsey.
Vice-county records. Britain: Derbyshire, Kirkcudbrightshire, Channel Islands.
Classification. Family Polypodiaceae (C.T.W.); Pteridaceae (Swale and Hassler); Adiantaceae (Stace). Order Pteridales (Swale and Hassler).
Illustrations. • Anogramma leptophylla. • Anogramma leptophylla (inter alia).
To view the illustrations with detailed captions, go to the Intkey interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2004 onwards. The ferns (Filicopsida) of the British Isles. Version: 3rd March 2008. http://delta-intkey.com’.
