Heteranthera dubia

Yesterday in Elkhart County, Indiana, I saw something that I think I've only seen once before, on a river in southern Missouri.... Heteranthera dubia in flower! This species was fairly abundant on a mudflat in a mitigation wetland, growing with Ranunculus longirostris. It is common to find water star grass, as it is known, vegetatively in northern Indiana lakes, often growing with the similar-looking (at least vegetatively) Potamogeton zosteriformis. The leaves of the latter have a distinct midrib, while those of H. dubia do not. It is interesting to note that this plant is in the same family as Pontederia cordata.