These organisms are microscopic, unicellular or filamentous. Microphytobenthos normally live in sedimentary shores, according to Wehr and Sheath in the book "Freshwater Algae of North America: Ecology and Classification."
Common microphytobenthos species living on the bottom of North-American rivers, lakes and sea coasts include:
Navicula
Gyrosigma
Nitzchia
Diploneis
Plagiotropis
Amphora
Fallacia
Cylindrotheca
Euglena
Staurophora
According to the 4Seas Project, macrophytobenthos include green algae (Chlorophyceae), brown algae (Phaeophyceae), red algae (Rhodophyceae), and plants of the family Potamogetonaceae.
These algae or seaweeds are rich in chlorophyll that gives their characteristic color. They can live in the benthic zone as individuals or colonies. These are common species:
Zostera marina (eelgrass)
Ulva lactuca (sea lettuce)
Cladophora rupestris
Codium fragile (spongeweed)
Codium tomentosum
Monostroma grevillei
Spongomorpha aeruginosa
The dominance of the pigment xanthophyll determines the brown color of these algae. According to Michael Guiry’s Seaweed Site, there are about 1800 species of brown algae, most living in marine environments. Some examples:
Fucus vesiculosus (bladderwrack)
Ascophyllum nodosum (Norwegian kelp)
Sargassum sp
Macrocystis pyrifera (giant kelp)
There are 6000 described species of red algae, as stated in Michael Guiry’s Seaweed Site. The red color results from the pigments phycoerythrin and phycocyanin. Examples include:
Atractophora hypnoides
Gelidiella calcicola
Lemanea fluviatilis
Lemanea fucina
Palmaria palmata (dulse)
Schmitzia hiscockiana
Chondrus crispus (Irish moss)
Mastocarpus stellatus (false Irish moss)
Ceramium
Potamogeton, the only family of macrophytobenthos able to produce flowers and fruit, is the largest genus. Some species:
Zannichellia palustris (horned pondweed)
Potamogeton alpinus
Potamogeton pectinatus (fennel pondweed)
Lepilaena marina
Lepilaena preissii
Althenia
Groenlandia
Stuckenia