The floating round leaves and yellow flowers of the rare yellow water-lily are found during the summer months on slower moving parts of the river’s channel. Protected yellow iris blooms along the banks of the river in the spring. Common reed, large cattail and tall sedge form dense stands along the banks of the river and in its shallows.
Non-native invasive species are also found along the banks of the river and in the lowland forests right next to native, often protected, plant species. The most widespread are goldenrod and panicled aster. Stands of Bohemian knotweed are also significant. North American boxelder, that spread from urban environments, is becoming more prevalent in poplar monoculture stands. These plants are dangerous for local ecosystems as they push native plant and animal species out of their natural environments.