Knotted Rush is a native North American rush distinguished by its distinctly jointed, or 'nodulose,' stems and leaves, which give the plant a segmented, knotted appearance unlike most other rushes. It grows in moist, often calcareous (calcium-rich) habitats such as lake shores, spring seeps, and wet prairies, where it forms loose colonies from creeping rhizomes. The spherical, brownish flower heads are arranged in compact clusters at the stem tips. It is an indicator species of high-quality, undisturbed wetland habitats and is less common than many other rush species in the region.
Best time to see a Knotted Rush
The best time to see a Knotted Rush is June–August, when about 67% of U.S. sightings happen, based on 1,035 research-grade iNaturalist observations.
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