| Synonym/Old Name | New Name | Taxonomy Group | ||
|---|---|---|---|---|
 | Oscillatoria fuscopurpurea | Bangia fuscopurpurea | Rhodophyta | more info |
 | Padina commersonii | Padina boryana | Phaeophyceae | more info |
 | Palisada perforata | Laurencia perforata | more info | |
 | Palmaria mollis | Devaleraea mollis | Rhodophyta | more info |
 | Papenfussiella kuromo | Myriocladia kuromo | more info | |
 | Parietochloris cohaerens | Ettlia cohaerens | Chlorophyta | more info |
 | Parietochloris incisa | Lobosphaera incisa | Chlorophyta | more info |
 | Pavlova lutheri | Diacronema lutheri | Pavlovophyceae | more info |
 | Pavlova salina | Rebecca salina | Pavlovophyceae | more info |
 | Pavlova viridis | Diacronema viridis | Pavlovophyceae | more info |
 | Pediastrum boryanum | Pseudopediastrum boryanum | Chlorophyta | more info |
 | Pediastrum simplex | Monactinus simplex | Chlorophyta | more info |
 | Pelvetia babingtonii | Silvetia babingtonii | Phaeophyceae | more info |
 | Phormidium neotenue | Oscillatoria tenuis | Cyanobacteria | more info |
 | Phycoseris reticulata | Ulva reticulata | Chlorophyta | more info |
 | Phymatolithon masonianum | Masoniana kraftii | Rhodophyta | more info |
 | Pila lusitanica | Botryococcus braunii | Chlorophyta | more info |
| Platychrysis pigra | Prymnesium pigrum | Coccolithophyceae | more info |
 | Plectonema boryanum | Leptolyngbya boryana | Cyanobacteria | more info |
 | Plectonema radiosum | Pseudophormidium radiosum | Cyanobacteria | more info |
Credits to Prof Leonel Pereira
