British ferns (Filicopsida)
Sporophyte. The rhizomes short, stout; decumbent or shortly creeping; bearing scales (densely scaly, with broad, soft scales).
Leaves distributed along the rhizomes, or aggregated terminally (?); to 30–100(–150) cm long; dying in the autumn (the base of the petiole decaying first); circinnate; compound; complexly divided; bipinnate with conspicuously divided pinnules, or tripinnate with undivided ultimate pinnules, or tripinnate with conspicuously divided ultimate pinnules. Pinnae 15–25 on each side of the leaf. The petioles shorter than the blades to longer than the blades (dark brown at the base and pale green above, with uniformly pale brown, ovate or ovate-lanceolate, entire scales, these few above and more numerous but not dense at the base); about 0.6–1.3 x the length of the blade (from two thirds its length to rather longer than it); vascularised by several discrete strands (derived via several leaf traces). Petiolar scales not golden brown (pale brown). Leaf blades in outline narrowly oblong to ovate (the lower pinnae twisted into the more or less horizontal plane). The longest pinnae the lowermost, or near the base of the blade (the 3 or 4 basal pairs about equal in length); 5–10 cm long. The pinnae not decreasing markedly in length basipetaly, the basal pinnae not or scarcely shorter than the longest pair. The lowest pinna with the lowest pinnule on the lower side much longer than the lowest one on the upper side, and often longer than the one or two adjoining it as well. The venation of the lamina open.
The sporangia superficial; aggregated in sori. The sori sub-orbicular (about 0.5–1 mm diameter, forming a row down either side of the segment); remaining discrete at maturity; with a true indusium. The indusia reniform and attached at the indentation; entire or sinuate, without glands. The mature spores monolete; without a perispore.
Distribution and habitat. Helophytic to mesophytic. In damp or wet woods, marshes, fens and wet heaths. Frequent throughout most of the British Isles.
Vice-county records. Britain: West Cornwall, East Cornwall, South Devon, North Devon, South Somerset, North Somerset, North Wiltshire, South Wiltshire, Dorset, Isle of Wight, South Hampshire, North Hampshire, West Sussex, East Sussex, East Kent, West Kent, Surrey, South Essex, North Essex, Hertfordshire, Middlesex, Berkshire, Oxfordshire, Buckinghamshire, East Suffolk, West Suffolk, East Norfolk, West Norfolk, Cambridgeshire, Bedfordshire, Huntingdonshire, Northamptonshire, East Gloucestershire, West Gloucestershire, Monmouthshire, Herefordshire, Worcestershire, Warwickshire, Staffordshire, Shropshire, Glamorgan, Breconshire, Radnorshire, Carmarthenshire, Pembrokeshire, Cardiganshire, Montgomeryshire, Merionethshire, Caernarvonshire, Denbighshire, Flintshire, Anglesey, South Lincolnshire, North Lincolnshire, Leicestershire, Nottinghamshire, Derbyshire, Cheshire, South Lancashire, West Lancashire, South-east Yorkshire, North-east Yorkshire, South-west Yorkshire, Mid-west Yorkshire, North-west Yorkshire, Durham, South Northumberland, North Northumberland, Westmorland, Cumberland, Isle of Man, Dumfriesshire, Kirkcudbrightshire, Wigtownshire, Ayrshire, Renfrewshire, Lanarkshire, Peeblesshire, Selkirkshire, Roxburghshire, Berwickshire, East Lothian, Midlothian, West Lothian, Fifeshire, Stirlingshire, West Perthshire, Mid Perthshire, East Perthshire, Angus, Kincardineshire, South Aberdeenshire, North Aberdeenshire, Banffshire, Moray, East Inverness-shire, West Inverness-shire, Argyll Main, Dunbartonshire, Clyde Isles, Kintyre, South Ebudes, Mid Ebudes, North Ebudes, West Ross, East Ross, East Sutherland, West Sutherland, Caithness, Outer Hebrides, Shetland. 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, 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.); Dryopteridaceae (Swale and Hassler); Dryopteridaceae (Stace). Order Dryopteridales (Swale and Hassler).
D. x uliginosa (Braun ex Doll) Kuntze ex Druce = D. cristata x D. carthusiana; D. x deweveri (J.T. Jansen) Wacht. = D. carthusiana x D. dilatata; D. x sarvelae Fraser-Jenk. & Jermy = D. carthusiana x D. expansa; D. x brathaica Fraser-Jenk. & Reichst. = D. filix-mas x D. carthusiana.
Illustrations. • D. carthusiana: as Lastrea spinulosa, Eng. Bot. 1855 (1886). • D. carthusiana: Sowerby and Johnson (1859). • D. x uliginosa (D. cristata x D. carthusiana): as Lastrea uliginosa, Eng. Bot. 1854 (1886). • 9 British Dryopteridaceae (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’.