We were sampling plots in the Delta in July 2016, and found a small clump of this plant – pickerelweed (Pontederia cordata). Generally considered a desirable native wetland plant, it happens to fall in the same botanical family as the baddest of the bad in the Delta – waterhyacinth (Eichhornia crassipes). What does family mean in the botanical world, anyway? Although native here, pickerelweed is at best considered “occasional” in the Delta. Waterhyacinth falls somewhere between “abundant” and a “scourge,” depending on the year of reference. While there are a number of similarities in appearance (particularly in the characteristics of the flower, which is the original basis of splitting species into families), these plants do not “behave” at all alike.

We would like to see more of pickerelweed in the Delta – and a lot less of waterhyacinth.

John Madsen, USDA ARS, Davis, CA