Unknown plant invading green-space

The pictured plant has been steadily increasing in area from 20 sq. ft. to 200 sq. ft.
in a period of two years. I would like to know what it is, how pervasive and if needed how to get rid of it. The area has a canopy of big leaf maple and 90 ft doug firs. The
floor is relatively dry about 90 feet across and 30 feet deep.

 

Looks like Lamium. Common name Dead nettle. If it has yellow flowers, it is possibly Lamium galeobdolon.

http://images.google.com/images?hl=...=lamium galeobdolon&um=1&ie=UTF-8&sa=N&tab=wi

 

This is a Class C Noxious Weed in WA.

http://www.nwcb.wa.gov/weed_info/lamiastrum_galeobdolon.htm