I see there are loads of Enteromorphas. How do you tell them apart?
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Ulva. The British seaweeds that that were in genus Enteromorpha are now
considered to be in the genus Ulva.
This could be Ulva intestinalis, as that species is generally considered to be the commonest. However, identification of the "gut weeds" to species level in the field is difficult. The degree and pattern of branching are now considered to be environmentally, not genetically, determined. To be sure I now use microscopic characters such as the arrangement of the cells, the chloroplast shape and the number of pyrenoids in the cells.
The definitive book is Green Seaweeds of Britain and Ireland, 2008. Edited by Juliet Brodie, Christine A Maggs and David M John. British Phycological Society. This has keys, colour photos, b&w photos, drawings.
Thank you. Is there also an equivalent for red algae?
Seaweeds of the British Isles is a work of several volumes published by the NHM. There are 5 volumes covering just the reds!
For most seaweeds we 'iSpot mariners' find the 'Seasearch' book below good enough. It has all the common reds, greens and browns.
Bunker, Brodie, Maggs & Bunker 2010 Seasearch guide to seaweeds of Britain & Ireland Marine Conservation Society.
More books to add to the list, and the bookshelf
One only needs to read as far as JoC's comment to see why I have been. I am gradually being educated by her and the Book she mentions. But I have close-studied a lot of the Ulvales lately and can say (emphasize), that it is very difficult to be certain this obviously tubular, distorted, twisted, intestine-like gutweed is what was proposed.
Now see my recent post -
The Book(s) in question -
The former is quite specialized, the latter the most useful
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