Cup plant
The flower-rich silphia is native to North America and was already investigated in Russia in the middle of the 20th century as a feed plant for ruminants, but was found to be useless because the animals did not like its flavour. In the last two decades, however, it has been established that the flavour does not matter to biogas plants and that silphia is therefore well suited as a biogas substrate. Silphia delivers high annual biomass yields from the second year of cultivation and provides plenty of food for pollinating insects during flowering. Silphia has also been recognised as a greening measure since 2018. This means that farms that cultivate silphia are "rewarded" with around 60 € per hectare per year.