This stoloniferous herbaceous perennial aquatic plant with basal leaf-rosettes and flower stalks grows to 0.7–2 m (2.3–6.6 ft) tall.

[5] It is one of several unrelated species of plants from low nutrient lakes known as isoetids, owing to their superficial similarity to Isoetes.

[7][8] Lobelia dortmanna is native to cool temperate regions of northern Europe (from the British Isles and northwest France to northwest Russia) and northern North America (both coasts; Newfoundland south to New Jersey and west to the Great Lakes in the east, and British Columbia south to Oregon in the west).

[9][10] The plant typically occurs in shallow water on sandy, peaty or rocky lakeshores, in pools, and in some kinds of wetlands.

Scientifically, such aquatic environments are designated as habitat type 3130: "Oligotrophic to mesotrophic standing waters with vegetation of the Littorelletea uniflorae and/or of the Isoëto-Nanojuncetea".