Looks like henbit to me. See:
http://www.ppws.vt.edu/scott/weed_id/lamam.htm

Define "problem" 8-) I've got bits of it here and there, and I find it
sort of pretty in a small way. It gets mowed along with the rest of the
plants, including grass, that live in my lawn, and I don't notice it much
after that. Not worth getting excited about, IMO. It seems to confine
itself to the lawn, and doesn't annoy me by showing up very often in the
flower beds, which I do keep weed-free.

Cheers,
Sue

--

Zone 6, South-central PA

"Tony Karp" wrote in message
...

http://www.techno-impressionist.com/weed1.htm

There are large patches of this on the lawn of a house I just bought.

Is it a weed?

Is it invasive?

Will it be a problem?

Thanks.