Marsh sow-thistles are closely related to the much more common perennial sow thistles. They resemble each other very much, the difference being that the leaves of the marsh sow-thistle are less regularly serrated and end in a long triangular tip. They also have a waxy coating that feels a bit oily. Marsh sow-thistles remain shorter and scraggier than perennial sow thistles. The plant grows well in nutrient-poor conditions. however, it takes several years to blossom due to the lack of nutrients. Marsh sow-thistles grow mostly on the leeward side of the beach ridge and low dunes on beach plains along the North Sea coast. They are rarely found in the flood mark.