It is a perennial herb[3] that grows in a wide variety of habitat types, including tundra and taiga and many areas further south with subalpine and alpine climates.

It is extremely variable in morphology, its form depending on both genetic makeup and environmental conditions.

[4] In general, it is a rhizomatous perennial herb forming mats or clumps, or growing upright.

The linear to lance-shaped leaves are usually 1 to 4 centimeters long and are oppositely arranged in pairs.

arenicola, is limited to the sand dunes adjacent to Lake Athabasca in central Canada.