Examples from the Web for knotgrass
Grim had then to go where flags and knotgrass pricked tiny, almost invisible holes in the ice.Grim: The Story of a Pike|Svend Fleuron
The hedgehog footed through the knotgrass slowly, grubbing with his snout to right and left of him."Wee Tim'rous Beasties"|Douglas English
The food comprises groundsel, knotgrass, chrysanthemum, and various other plants.
Among various foods that have been mentioned for it are raspberry, ivy, and knotgrass.
It feeds on low-growing plants, such as knotgrass and dock, and has been reared from the egg in August and September.