| Noun | 1. | genus Juncus - type genus of the Juncaceae; perennial tufted glabrous marsh plants of temperate regions: rushesliliopsid genus, monocot genus - genus of flowering plants having a single cotyledon (embryonic leaf) in the seed common rush, Juncus effusus, soft rush, bullrush, bulrush - tall rush with soft erect or arching stems found in Eurasia, Australia, New Zealand, and common in North America |