British ferns (Filicopsida)
Polypodium australe Fée; ~P. vulgare.
Sporophyte. The rhizomes rather stout (fleshy); creeping (on or below the surface); bearing scales (densely clothed with reddish-brown, lanceolate scales).
Leaves distributed along the rhizomes; to 10–40 cm long; persistent; simple, or compound; if not truly pinnate, conspicuously, pinnately lobed (and deeply pinnatifid); when truly pinnate, simply divided (once pinnate, the pinnae broad-based). The petioles jointed and ultimately abscising at the point of attachment to the rhizome. Leaf blades in outline oblong to ovate, or ovate-triangular (mostly less than twice as long as wide, with 9–22 lobes or pinnae on each side, these often bent upwards from the main axis, the longest of them (3.5-)4.5–6.0(-7.5)cm long and the lowest usually hardly shorter than those above; the lobes or pinnae oblong or oblong-lanceolate, usually narrowly acute, and always toothed). The venation of the lamina reticulate, or open.
The sporangia superficial; exposed; aggregated in sori. The sori when young, mostly elongated (broadly elliptic); remaining discrete at maturity; not sunken; naked and neither indusiate nor pseudo-indusiate. Paraphyses present in the sporangia. The annuli (4–)5–10(–19) celled. The mature spores monolete; with a perispore.
Distribution and habitat. On base-rich substrates and on neutral substrates. In moist places, mostly on base-rich rocks, sometimes on tree-trunks. Scattered in Ireland, western Britain north to central Scotland, in southern England to east Kent, also Guernsey.
Vice-county records. Britain: West Cornwall, East Cornwall, South Devon, North Devon, South Somerset, North Somerset, Dorset, Isle of Wight, South Hampshire, West Sussex, East Sussex, East Kent, West Kent, Middlesex, East Gloucestershire, West Gloucestershire, Monmouthshire, Herefordshire, Worcestershire, Staffordshire, Shropshire, Glamorgan, Breconshire, Radnorshire, Carmarthenshire, Pembrokeshire, Cardiganshire, Montgomeryshire, Merionethshire, Caernarvonshire, Denbighshire, Flintshire, Anglesey, Derbyshire, Cheshire, West Lancashire, Mid-west Yorkshire, Westmorland, Cumberland, Isle of Man, Dumfriesshire, Kirkcudbrightshire, Ayrshire, Midlothian, Fifeshire, East Perthshire, Argyll Main, Clyde Isles, Kintyre, South Ebudes, Channel Islands. Ireland: South Kerry, North Kerry, West Cork, Mid Cork, East Cork, Waterford, South Tipperary, Limerick, Clare, North Tipperary, Kilkenny, Wexford, Carlow, Leix, South-east Galway, West Galway, North-east Galway, Offaly, Kildare, Wicklow, Dublin, Meath, West Meath, Longford, Roscommon, East Mayo, West Mayo, Sligo, Leitrim, Cavan, Louth, Monaghan, Fermanagh, East Donegal, West Donegal, Tyrone, Armagh, Down, Antrim, Londonderry.
Classification. Family Polypodiaceae (C.T.W.); Polypodiaceae (Swale and Hassler); Polypodiaceae (Stace). Order Polypodiales (Swale and Hassler).
The sterile P. x shivasiae Rothm. = P. interjectum x P. cambricum.
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’.