''Polysiphonia ceramiaeformis'', also called banded siphon weed, is a small red algae ('' Rhodophyta''), in the genus '' Polysiphonia''. Individuals are irregularly branched with the branches extending up to from a central node and ending in dense tufts of fibres.Maggs, C.A. and Hommersand, M.H. 1993. ''Seaweeds of the British Isles Volume 1. Rhodophyta Part 3A Ceramiales.'' The Natural History Museum, London

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. It is densely branched and attached by tangled prostrate axes. All axes are ecorticate. The

rhizoids Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the root hairs of vascular land plants. Similar structures are formed by some fungi. Rhizoids may be uni ...

are numerous

Reproduction

The plants are dioecious. The alga bears spermatangial branches on a cylindrical axis.

Cystocarp A cystocarp is the fruiting structure produced in the red algae after fertilization, especially such a structure having a special protective envelope (as in '' Polysiphonia)''. The structure from which carpospore A carpospore is a diploid spore p ...

s are oval with a narrow ostiole. The tetraspores cells divide to forms cells in fours, these occur in a spiral series.

Habitat

In pools at low water in sheltered sites.

Distribution

Very rare on the

British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...

.Hardy, F.G. and Guiry, M.D. 2003. ''A Check-list and Atlas of the Seaweeds of Britain and Ireland.'' The British Phycological Society. Recorded from a few sites in

Dorset Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset. Covering an area of , ...

,Batters, E.A.L. 1902. A Catalogue of The British Marine Algae. supplement to ''Journal of Botany'' 1902 pp.80 - 81 also recorded from north west

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

and the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western Europe, Western and Southern Europe and Anatolia, on the south by North Africa ...

References

Rhodomelaceae {{rhodophyta-stub