Observations by ratanawanno

https://en.wikipedia.org/wiki/Nuphar_lutea

Nuphar lutea has a long history of usage as a valued food source. The field of archaeobotany documents this species’ tubers and charred seeds present in Vologda River digs in northern Russia since Early Neolithic times (ca 10,000 years BCE).[24] The author of Edible and Medicinal Plants offered the following summary of this species’ wide usage in the Native American diet, where harvesting was done by canoe in late summer and early autumn:

Native people gathered the thick rootstocks in winter and spring, boiled or roasted them for several hours, then peeled them to expose their sweet, gluey contents. Rootstocks were also sliced, dried and ground into meal or flour. The starchy seeds can be difficult to remove, so the tribes rotted the fruits until the pods became soft. The heated seeds swell like poor-quality popcorn, making a crunchy snack.”[25]