Medusa head (Taeniatherum caput-medusae) is an invasive plant. It was first detected in Oregon in 1903.
Medusahead was notorious as one of the worst range weeds in the Western U.S. fifty years ago. Medusahead crowds out and kills native plants including sagebrush, squirreltail, and needlegrass, which results in a severely degraded wildlife habitat. Particularly alarming to the fire-ravaged West is medusahead's propensity to burn after its seasonal dieoff, and the frequent fires suppress less resistant native plants. Medusahead's high content of silica, a gritty mineral that wears away teeth, makes it highly unsuitable for grazing.