I believe it may be Quack grass
It will spread quickly thru the lawn

http://www.gov.on.ca/OMAFRA/english/...uack_grass.htm

"Gene Moon" wrote in message
...
Can anyone tell me what this is? I never had this last year and all of
sudden its growing in. It looks like grass, but something tells me it is
not. I'm not sure.

http://www.chopinsociety.com/grass.htm

TIA
Gene