Station 7 | Yellow mountain-avens

Yellow mountain-avens Dryas drummondii

Dryas (mountain-avens) is a small genus within the rose family (Rosaceae) which grows worldwide in arctic and alpine regions.

Dryas drummondii (yellow mountain-avens) is the only Dryas species which is able to form a symbiosis with nitrogen-fixing bacteria of the genus Frankia. This symbiosis leads to the formation of new plant structures, so-called multi-lobed nodules, which can reach a significant size and look similar to walnuts. Within these nodules, Frankia bacteria infect plant cells and fix atmospheric nitrogen to make it available to the yellow mountain-avens. In return, the bacteria receive the photosynthesis product sugar as nutrition from the plant.

Header: Root nodules of yellow mountain-avens. © Grafik: BotMuc/Tanja Simon