Polysiphonia elongella Harvey in W.J. Hooker Hardy, F.G. and Guiry, M.D. 2003 A Checklist and Atlas of the Seaweeds of Britain and Ireland. The British Phycological Society. is a branched species of marine red algae in the genus in the Polysiphonia in the Rhodophyta.
Description This marine alga grows as small cylindrical thalli branching to about 10 cm long. It grows as an erect axis attached by a disk-like holdfast. The main axis is unbranched towards the base but bears lateral branches higher up. Each erect axes is composed of a polysiphonous axis with a central row of cells surroundedJones, E. 1962 A key to the genera of British seaweeds reprinted from Field Studies Volume 1 (4) p23 4 perixial cells all of the same length.Maggs, C.A. and Hommersand, M.H. 1993. Seaweeds of the British Isles Volume 1 Rhodophyta Part 3A Ceramiales The Natural History Museum London The branches, unlike Polysiphonia elongate, are only slightly constricted at their base.Newton, L. 1931. A Handbook of the British Seaweeds. British Museum LondonHarvey, W.H. 1841. A Manual of the British Algae. London Cortication filaments grow downwards in the grooves between the periaxial cells and lower down these form a complete cortication. Trichoblasts are borne near the apices.
Reproduction Globose cystocarps and bisporangia are recorded, the tetrasporangia are sparse.
Habitat Grows below low-water on sheltered shores.Morton, O. 2003 The marine macroalgae of County Donegal, Ireland. Bulletin of the Irish Biogeographical Society no.27
Distribution The species is recorded from Ireland, Great Britain, including the Isle of Man, the Shetland Islands and the Channel Islands. The few records from Northern Ireland are old and require confirmation.Morton, O. 1994. Marine Algae of Northern Ireland. Ulster Museum Also recorded from France and the Mediterranean.
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