button grass

• buttongrass, button-grass

From button +‎ grass.

button grass (uncountable)

1. (chiefly Australia) Any of several grasses with round or globular flower heads; especially Gymnoschoenus sphaerocephalus, a tussock-forming sedge especially of western Tasmania, forming distinct plains; and Dactyloctenium radulans, an annual grass of mainland Australia. [from 19th c.]
   • 1997, Richard Flanagan, chapter 75, in The Sound of One Hand Clapping‎, New York: Atlantic Monthly Press, pages 377–378:

     [T]he ceiling swelled in waves like an ocean, like a buttongrass plain, like the pocked earth stripped of its trees […] .

   • 2004, Nicholas Shakespeare, In Tasmania, Harvill Press, p. 73:

     Button-grass plains grew in peaty soil to the water's edge.