marsh-fleawort

from The Century Dictionary.

• noun A swamp or marsh plant, Senecio palustris, found in high northern latitudes in North America, Greenland, Europe, and Asia, extending southward in the western hemisphere to Iowa and Wisconsin. It has spatulate, entire, radical leaves, those of the stem being few and toothed. The heads are numerous, mostly in a terminal corymb, the rays pale yellow but showy.