British ferns (Filicopsida)


L. Watson and M. J. Dallwitz

Blechnum spicant (L.) Roth


Lomaria spicant (L.) Desv., B. spicant (L.) Smith.

Sporophyte. The rhizomes stout; short, erect; bearing scales (with brown, lanceolate scales). Plants bearing markedly different fertile and sterile leaves (the linear, sorus-bearing pinnae of the fertile leaves narrower than those of the sterile leaves, and widely separated).

Leaves aggregated terminally; to 15–50(–75) cm long (the sterile leaves 10–50 cm, the fertile ones 15–75 cm); persistent; simple (in that the “pinnae” of the pectinate sterile leaves have broadened, contiguous bases), or compound (clearly so in the fertile leaves, where the pinnae are narrow-based and distant); when sterile and recognised as simple, conspicuously, pinnately lobed; when fertile, clearly compound and simply divided. Pinnae about 15–40 on each side of the leaf (numerous, fewer in fertile leaves). The petioles shorter than the blades (not more than a third as long as the blade and often much less, dark brown, scaly at the base); vascularised by several discrete strands. Leaf blades in outline very narrowly elliptic; somewhat leathery to ‘herbaceous’. The longest pinnae around the middle of the blade; 1–2.5 cm long (1–2cm X 3–5 mm in sterile leaves, 1–2.5 cm X 1–2 mm in fertiles leaves). The venation of the lamina mostly open.

The sporangia marginal to superficial (so close that the longitudinally elongated indusium could be confused with the margin); initially aggregated in sori. The sori elongated (forming continuous lines along the length of the fertile pinna, on either side of its midrib); finally becoming confluent when mature (and appearing to cover the entire underside of the pinna at maturity); with a true indusium (this first whitish, then brownish, elongated along the outside of the sorus, between it and the very narrow margin of the lamina). The mature spores monolete; without a perispore.

Distribution and habitat. On neutral substrates and on acid substrates (calcifuge). In woods, heaths, moors, grassy places and rocky slopes, mostly on acid soils in rather dry places. Common throughout most of the British Isles except central and central-eastern England.

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.); Blechnaceae (Swale and Hassler); Blechnaceae (Stace). Order Athyriales (Swale and Hassler).

Special key character. The pinnae of the sterile leaves with broadened, contiguous bases.

Illustrations. • B. spicant: as Lomaria spicant, Eng. Bot. 1885 (1886). • B. spicant: Sowerby and Johnson (1859). • Blechnum spicant (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.’.