Polysiphonia ceramiaeformis explained

Polysiphonia ceramiaeformis, also called banded siphon weed,^[1] is a small red algae (Rhodophyta), in the genus Polysiphonia. Individuals are irregularly branched with the branches extending up to 5.5cm (02.2inches) from a central node and ending in dense tufts of fibres.^[2]

Description

This small red algae lacks a clearly to be seen main axis. Each branch is formed of axial cells with 10 - 12 periaxial cells of equal length, with forcipate incurved tips.^[3] It is densely branched and attached by tangled prostrate axes. All axes are ecorticate. The rhizoids are numerous^[2]

Reproduction

The plants are dioecious. The alga bears spermatangial branches on a cylindrical axis. Cystocarps are oval with a narrow ostiole. The tetraspores cells divide to forms cells in fours, these occur in a spiral series.^[2]

Habitat

In pools at low water in sheltered sites.^[2]

Distribution

Very rare on the British Isles.^[4] Recorded from a few sites in Dorset,^{[5] [2]} also recorded from north west France and the Mediterranean.^[2]

Notes and References

1. Web site: Algae Base: Polysiphonia ceramiiformis P.Crouan & H.Crouan . 31 January 2017.
2. Maggs, C.A. and Hommersand, M.H. 1993. Seaweeds of the British Isles Volume 1. Rhodophyta Part 3A Ceramiales. The Natural History Museum, London
3. Jones, W.E. 1964(4) A key to the genera of the British seaweeds. Field studies (reprinted pp 1-32
4. Hardy, F.G. and Guiry, M.D. 2003. A Check-list and Atlas of the Seaweeds of Britain and Ireland. The British Phycological Society.
5. Batters, E.A.L. 1902. A Catalogue of The British Marine Algae. supplement to Journal of Botany 1902 pp.80 - 81