Algae
Lack of expertise means that the tables below only represents of some of the species that are present, and in some cases uncertainty is indicated by brackets and a question mark.
Below is a list of Algae, presented in alphabetical order. A photograph (where available) of a specimen found somewhere in the area may be viewed by clicking on the scientific name.
| Species | Common Name | Location |
| Achnanthes | Diatom | Alexandra Lake 08/01/2018 |
| Ankistrodesmus gracilis (possibly) | Colonial alga | Perch Pond 18/04/2018 |
| Cladophora | Green alga | Capel Road garden 09/11/2015 |
| Closterium | Desmid | Alexandra Lake 08/01/2018 |
| Cosmarium | Desmid | Harpenden Road garden pond 01/01/2018 |
| Cymatopleura | Desmid | Harpenden Road garden pond 01/01/2018 |
| Cymbella | Diatom | Harpenden Road garden pond 01/01/2018 |
| Desmidium | Desmid | Harpenden Road garden pond 01/01/2018 |
| Diatom | Diatom | Capel Road garden 01/12/2015 |
| Enteromorpha | Gut Weed | Wanstead Flats, Jubilee Pond 13/07/2011; Wanstead Park, Heronry Pond |
| Euglena | Euglena Flagellate | Harpenden Road garden pond 01/01/2018 |
| Euglena | Euglena Flagellate | Capel Road garden, 29/03/2018 |
| Eunotia | Diatom | Alexandra Lake 08/01/2018 |
| Gonium | Colonial alga | Perch Pond, Wanstead Park, 18/04/2018 |
| Gymnodinium ? | Flagellate | Capel Road garden pond 27/12/2017 |
| Hantzschia | Diatom | Capel Road garden 29/11/2015 |
| Klebsormidium ? | Capel Road garden, 18 December 2017 | |
| Navicula | Diatom | Harpenden Road garden pond 01/01/2018 |
| Navicula | Diatom | Alexandra Lake, 8 January 2018 |
| Oscillatoria | Capel Road garden pond, 26 August 2019 | |
| Pediastrum | Green Algae | Harpenden Road garden pond 01/01/2018 |
| Peridinium | Flagellate | Capel Road garden 19/11/2015 |
| Phacus | Euglena Flagellate | Alexandra Lake 08/01/2018 |
| Scenedesmus | Green Algae | Harpenden Road garden pond 01/01/2018 |
| Scenedesmus | Green Algae | Harpenden Road garden pond 01/01/2018 |
| Spirogyra | Green Algae | Harpenden Road garden pond 01/01/2018 |
| Staurastrum (natator?) | Desmid | Harpenden Road garden pond 01/01/2018 |
| Staurastrum | Desmid | Harpenden Road garden pond 01/01/2018 |
| Synura | Colonial Alga | Capel Road garden pond, 9 April 2018 |
| Synura | Colonial Alga | Perch Pond, Wanstead Park, 18/04/2018 |
| Trachelomonas | Euglena | Harpenden Road garden pond 01/01/2018 |
| Trentepohlia aurea | Green Algae | Bush Wood 07/11/2007 |
| Trentopohlia (aurea?) | Green Algae | St. Mary's churchyard, Wanstead 07/02/2016 |
| Ulothrix | Green Algae | Harpenden Road garden pond 01/01/2018 |
| Ulotrichales (Order) | Green Algae | Harpenden Road garden pond 01/01/2018 |
| Volvox | Volvox | Capel Road garden 17/12/2017 |