S mag 8th may

[toecrusher]

28d type of grass, agropyron repens, which has a yellow white underground creeping stem c-r-k. (i can only find quackgrass as an answer)

[johnalex]

Couch would be favourite. 

[gen2]

I agree Couch would seem to be the answer.

In the UK, Agropyron repens is called couch grass, in the US it is more often called quackgrass. Is there any possibility of the R and the K being wrong?

[barender]

'r' and 'k' are wrong - it is couch grass