| | Ferns (Filicopsida) of Britain and Ireland |
“Wall Spleenwort, Wall Rue”.
Sporophyte. The rhizomes short, creeping; bearing scales (when young, the scales dark, subulate). Plants with no clear distinction into fertile and sterile leaves.
Leaves aggregated terminally; to 3–12(–15) cm long; persistent; compound; complexly divided; bipinnate with conspicuously divided pinnules, or bipinnate with conspicuously divided pinnules to tripinnate with undivided ultimate pinnules (the pinnae 3–5 on each side of the leaf, the pinnules rarely more than 5 and often only 3, usually undivided but the lowermost of them sometimes trisect, the ultimate segments crenate or dentate and varying in shape on different plants). Pinnae 3–5 on each side of the leaf. The petioles about as long as the blades to longer than the blades (up to twice as long, their bases blackish, the rest dull green like the narrowly winged rachis and the rest of the leaf, glandular and with a few hair-like scales when young); vascularised via a single strand (representing fusion of a pair of leaf traces). Leaf blades in outline ovate-triangular, or lanceolate-triangular; leathery. The longest pinnae the lowermost; 1–3 cm long. The venation of the lamina open.
The sporangia superficial; initially aggregated in sori. The sori linear elongated (about 2 mm long, borne along the veins and more or less longitudinally along the segments, two or more); finally becoming confluent when mature; with a true indusium. The indusia attached on one side along a vein; whitish, finally crenulate. Paraphyses absent. The mature spores monolete; with a perispore.
Distribution and habitat. On base-rich substrates. Basic rocks and all kinds of base-rich walls, including mortar in acid regions. Common 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, Orkney islands, Shetland, 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.); Aspleniaceae (Swale and Hassler); Aspleniaceae (Stace). Order Aspleniales (Swale and Hassler).
A. x murbeckii Dörfl. = A. ruta-muraria x A. septentrionale.
Comments. The base of the petiole blackish, the rest dull green like the narrowly winged rachis and the rest of the leaf.
Illustrations. • A. ruta-muraria: Eng. Bot. 1880 (1886). • A. ruta-muraria: Sowerby and Johnson (1859). • A. x clermontiae (A. ruta-muraria x A. trichomanes): Eng. Bot. 1879 (1886). • 9 Aspleniaceae of Britain and Ireland (inter alia). ASPLENIACEAE. 1741, Asplenium adiantum-nigrum; 1742, Asplenium trichomanes; 1743, Asplenium viride; 1744, Asplenium marinum; 1745, Asplenium ruta-muraria; 1746, Aslpenium x-alternifolium (A. septentrionale x A. trichomanes); 1747, Asplenium septentrionale. 1748, Phyllitis scolopendrium. 1749, Ceterach officinarum. Pteridaceae. 1750, Anogramma leptophylla. Blechnaceae. 1751, Blechnum spicant. Hypolepidaceae. 1752, Pteridium aquilinum. Adiantaceae. 1753, Adiantum capillus-veneris. Hymenophyllaceae. 12754. Trichomanes speciosum; 1755, Hymenophyllum tunbrigense; 1756, Hymenophyllum wilsonii. Osmundaceae. 157, Osmunda regalis. Ophioglossaceae. 1758, Botrychium lunaria; 1759, Ophioglossum vulgatum; 1760, Ophioglossum lusitanicum. From Sowerby and Johnson (1863, the family assignments following Swale and Hassler).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2004 onwards. Ferns (Filicopsida) of Britain and Ireland. Version: 5th August 2019. delta-intkey.com’.
