An analysis of about 100 populations of 39 taxa of Epilobium sect. Epilobium showed quercetin 3‐0‐rhamnoside and glucoside and myricetin 3‐0‐rhamnoside and glucoside to be present in most species, with the arabinosides present in some and in much smaller quantities. Kaempferol 3‐0‐rhamnoside was also present in some populations of some entities in small quantities. Variability, particularly in the presence of myricetin 3‐0‐rhamnoside and quercetin 3‐0‐glucoside, was characteristic of some species, especially those of Australia and New Zealand.