British ferns (Filicopsida)
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 blades to longer than the blades; 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. • A. leptophylla: as Gymnogramma, Eng. Bot. 1843 (1886). • A. leptophylla: Sowerby and Johnson (1859). • Anogramma leptophylla (inter alia).
To view the illustrations with detailed captions, go to the 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. British ferns (Filicopsida). Version: 4th January 2012. http://delta-intkey.com’.