Polysiphonia opaca

Polysiphonia opaca
Scientific classification
Clade:	Archaeplastida
Division:	Rhodophyta
Class:	Florideophyceae
Order:	Ceramiales
Family:	Rhodomelaceae
Genus:	Polysiphonia
Species:	P. opaca
Binomial name
	Polysiphonia opaca; (C.Agardh) Moris & De Notaris

Polysiphonia opaca (C.Agardh) Moris et De Notaris is a small marine alga in the division Rhodophyta.

Description

This small seaweed consists of tufts of branches no more than 6 cm long.^[1] The tufts are of erect branches each consisting a series of axial cells surrounded by about 20 periaxial cells all of the same forming a "collar" around the axis. There is no cortication and the plant is attached by rhizoids which attach the plant to a surface.^[1] This alga may be confused with Lophosiphonia reptabunda, this alga has however a turf-like habit and is less than 3 cm high unlike P. opaca which grows to over 5 cm high.^[1]

Distribution

Very rare, recorded from the south of Wales.^[2] Europe: British Isles to Spain, West Indies and E.Australia.^[1]

References

^ ^a ^b ^c ^d Maggs, C.A. and Hommersand, M.H. 1993. Seaweeds of the British Isles Volume 1 Rhodophyta Part 3A Ceramiales. The Natural History Museum, London. ISBN 0-11-310045-0
^ Hardy, F.G. and Guiry, M.D. 2003 A Check-list and Atlas of the Seaweeds of Britain and Ireland. British Phycological Society ISBN 0-9527115-16

[Maggs_93-1] Maggs, C.A. and Hommersand, M.H. 1993. Seaweeds of the British Isles Volume 1 Rhodophyta Part 3A Ceramiales. The Natural History Museum, London. ISBN 0-11-310045-0

[2] Hardy, F.G. and Guiry, M.D. 2003 A Check-list and Atlas of the Seaweeds of Britain and Ireland. British Phycological Society ISBN 0-9527115-16

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