Scientists feared the plume would prevent sunlight from reaching the grass beds, suffocating them.
From the washingtonpost.com
Radioactive iodine falls from the plume in rainfall and settles on the grass, where it's eaten by cows and builds up in their milk.
From the usatoday.com
Growing 2-8 feet tall, and topped by a large, plume-like, golden-brown seed head, the grass is attractive in the fall when the flowers produce dangling yellow stamens.