This aquatic lobelia is a partly submerged perennial bearing a mat of rosettes, oblong, deep green leaves. Pale blue to pale violet flowers are borne of racemes above the water summer to fall. Perfect along streams or where conditions are moist to boggy and acidic. Grows to a height of 3 inches and 1 inch wide. The American Horticulture Society ranks this as one of the top 75 plants for the garden.