Mullumbimby couch
Australian
noun
The sedge Kyllinga monocephala (also known as K. brevis), bearing small whitish spikelets in dense clusters and long rhizomes, which is native to tropical America, Africa, and Asia and widely naturalized in Australia as a weed of damp lawns and pasturage.
Origin
Early 20th century; earliest use found in William Robert Guilfoyle (1840–1912).