Identify that alga:
Web-based key to genera -31: unicells with chloroplasts

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filaments

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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) 
 
  
 
 

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UNICELLS   Click on the thumbnail for a larger image

Cell with 1 or more chloroplasts

 
  Cell of symmetrical structure, with a rigid silica case, usually intricately ornamented. May be variously symmetrical; attached, motile, or forming chains or colonies.   Diatoms
  Cell of symmetrical structure, apparently composed of two identical halves, sometimes divided by a constriction, with chloroplast(s): no silica case.   Desmids
 
     
  Cell not regular, not composed of two halves key under construction
 
Cell motile by means of flagellae (but may lose them, or be inactive)
 
 

Cell spherical, oval or elongated, 1 flagellum responsible for movement (also has a second inactive one inside the cell),

 

Cell elongated, can show variations in shape (euglenoid movement). Pellicle may have striations.



Euglena
 

Cell may be elongated, oval or spherical, pellicle may have striations but incapable of euglenoid movement. Not compressed in cross-section.

Lepocinclis
 

Cell may be elongated, oval or spherical, compressed in cross-section.

 
Phacus
 

Cell enclosed in a flask-shaped lorica


Strombomonas (Trachelomonas)
 
   
       
 
Cell non-motile
  
       
       
       

Cell without chloroplast(s): chlorophyll evenly distributed through cytoplasm : Cyanobacteria ("Blue-Green Algae")

 (not many cyanobacterial species are single-celled)
  Cell spherical to club-shaped, attached. In older cells may form a short filament with a spherical spore at the tip, enclosed in a thin sheath. Chamaesiphon
  Cell short-cylindrical or constricted in the middle, no sheath       Synechococcus
         

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John Kinross