Tribonema

Tribonema is a genus of simple, filamentous freshwater algae belonging to the class Xanthophyceae, commonly known as yellow-green algae. These algae are characterized by their asexual spores, which form within cells and are released when the filaments break into H-shaped pieces.12

Yellow-green algae, including Tribonema, were once grouped with green algae but are now understood to be more closely related to brown algae based on molecular evidence. They possess distinct features such as oil as a food reserve and motile cells with unequal flagella.2