Medusahead, an inedible grass species with sharp pointy tips is spreading rapidly through western part of the United States. Researchers express concern over the uncontrollable growth of the worthless grass and say that unless controlled, the grass will invade into millions of hectares of grazing land and create a crisis for animals dependent on native grass.

Seema Mangla, a plant ecologist at Oregon State University, Corvallis who led a study on this particular grass describes it as a devilish species because it “is absolutely not of any worth".

The study titled “Every animal avoids it” finds that the grass has a long, curly and snakelike seed stems (hence the name Medusahead) which are very stiff and sharp like needles. The grass is filled with inedible silica and has negligible nutrients. The grass piles up fast as no animal wants to eat it. "It's part of a huge change in vegetation structure," said Mangla.

Medusahead is spreading with a growth rate of 12% every year in 17 western states. Mangla informs that even though the grass came to the U.S. in 1880 from the Mediterranean region and currently has invaded only more than 1 million hectares, the steady growth of the grass in recent years is a cause of concern. It may overshadow the growth of not just the native grasses, but even cheatgrass, another invader grass but definitely more nutritive.

Measures such as mowing or use of herbicides to control the growth of the grass have proved futile. "We need to understand its growth dynamics, what makes it such a successful invader, and then we can figure out better ways to disrupt it," said Mangla.

Mangla and her team of researchers did a comparative study of the growth pattern of various native grasses as well Medusahead over two seasons at the Eastern Oregon Agricultural Research Center in Burns and Medusahead came out as the clear winner.

“It's a good study, and shows why medusahead can be so competitive," said Joseph Ditomaso, an invasive plant ecologist at the University of California, Davis. "Since animals won't eat it, Medusahead essentially creates its own thatch layer, which is a great tactic for preventing seeds from sprouting, as every gardener knows.”