cheatgrass

From cheat +‎ grass (reputedly because farmers felt cheated when wheat yields were lower because of cheatgrass invading their fields).

• IPA^(key): /ˈtʃiːtɡɹɑːs/

cheatgrass (countable and uncountable, plural cheatgrasses)

1. Bromus tectorum, drooping brome, native to Europe, thought to create an ecology prone to annual fires in many US areas.

• 2006, Thomas Pynchon, Against the Day, Vintage 2007, p. 98:

  It took maybe nine or ten years more of westward drift, over the rolling prairie, through the cheatgrass, the sage grouse exploding skyward […]