Streamside fleabane looks similar to our other fleabanes (pale purple disk-shaped flowers), but is unique in that it is colony forming and enjoys moist soils. Plant this species where you have a little sprinkler overspray, or perhaps near a vegetable garden. Good companions include nettle-leaf giant hyssop, Eaton's aster, lewis monkeyflower, pearly everlasting, sneezeweed, and fireweed.