Identify that alga:
Web-based key to genera -1

Many of these pages are presented as tables, and are best viewed in Landscape.

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NOTE: this key is a bit different from the traditional dichotomous key; I've based it on how I think I make IDs myself, at least in the early stages.
It does not cover all genera listed in the "Freshwater Algal Flora of the British Isles", only more common ones, and mainly ones I have images of.
Inevitably, with more difficult specimens, you may need to use a good traditional key also. See also links to other web-based keys listed on the 'links' page.
I'd appreciate any feedback from anyone trying to use it: does it make sense? are any parts ambiguous?

Algal Search Sitemap and quick links

Jump to:
(filename)
start

 (search1)
filaments

(search2)
branched
+chloroplast
(search3)
unbranched
+chloroplast
(search4)
 
 
Colonies and coenobia
+chloroplast
(search10)
planktonic,
with sheath
 
(search11)
planktonic,
without sheath  
(search12)
 attached
cushion

(search13)
 attached,
flat plate
(search13) 
attached,
sheath

(search14)
 
 
Colonies and coenobia : Cyanobacteria
(search21)
planktonic,
with sheath
(search21)
 
 
 
 
 
Unicells

(under development)
 + chloroplast(s)
(search31)

(under development)
Desmids

(searchdesmid)
non-flagellate cells
without case
(under development)
 in silica case
= diatoms
(under development)
flagellate cells

(under development)
 
 
 
 

no chloroplast:
Cyanobacteria
(search31)

 
 
 
 

Click on the underlined text link to jump to the next step: Click on the thumbnail for a larger image
Specimen is a: filament (2 or more cells linked in a linear series)
     
  colony (more than 2 cells in a group),
  or sometimes more precisely a coenobium: a definite number of cells, usually a multiple of 4, often arranged in a regular manner
     
  Unicell one (or two) cells only; sometimes divided into semicells  
     

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John Kinross