Human Ecology, Volume 40, Number 5 - SpringerLink
Manna grass (mainly but not exclusively G. fluitans) used to be widely gathered in most lowland areas of the present territory of Poland and western and southern Belarus. It had an important function as a component of tribute paid to local landowners by villagers, which led to the persistence of manna gathering even when this was not sustainable for peasants themselves. Manna grass was always an expensive food due to its time consuming gathering, but appreciated for its sweet taste and often served as dessert. In the nineteenth century marshes shrank significantly and the payment of tribute disappeared from the local economy, which gradually led to the total abandonment of Glyceria use around 1914. This article provides a detailed overview of Glyceria use as food within the borders of the former Polish-Lithuanian Kingdom (now Poland, Lithuania, western Belarus and western Ukraine) based on archaeobotanical, historical and ethnographic sources. The evidence for the continued use of manna since at least medieval times is abundant in historical accounts and ethnographic studies, but little has been reported in archaeobotanical findings due to the relatively small amounts of Glyceria consumed.
Via Dorian Q Fuller