United States, Illinois, Vermilion, Collison's Seep Swamp, north side of Collison Branch and south of the Chicago and Eastern Illinois Railroad. About 1 mile directly northeast of Collison; Collison 7.5 minute topographic map.
T. 21N, R. 13W, E1/2 NW1/4 Sect. 35
Blue flowered shrub about 10 feet tall infrequent in swamp below seeps.