Potamogeton trichoides is a species of aquatic plant known by the common name hairlike pondweed,[2] native to Europe and western Asia where it grows in calcareous, usually nutrient-rich standing or slow-flowing water.

Hairlike pondweed is an aquatic perennial that dies back each winter into a large number of asexually produced resting bodies called turions.

[6] Hairlike pondweed grows predominantly in standing water including ponds, lakes, ditches, canals and slow-flowing rivers and streams.

[3] It is often an early succession species, colonising newly created habitats such as ditches and flooded gravel pits,[3] but sometimes is abundant in alkaline, low altitude lakes.

[9] It often grows with other nutrient tolerant macrophytes such as Myriophyllum spicatum, Potamogeton crispus, P. pusillus and Ranunculus circinatus.

[7] However, it is placed in various threat categories in parts of its range, for example it is Vulnerable in the Czech Republic,[10] and Germany (although still widespread along all major river systems there),[11] and Critically Endangered in Switzerland.