It's spotted deadnettle or Lamium maculatum.

If it has yellow flowers it is also called yellow archangel and is very pretty where it can be contained but is also very invasive.Posy Pet

Thank you very much for answering my question. Gardengal48 was right as I goolgled it right a way and saw the pictures of spotted dead nettle was exectly what I picked in the forest. They bloom in early summer through fall. That's why I still see some purple flowers on them.
Thank you SO much and I just love the gardenweb :)

You did note that posy pet said they are very invasive? Very should be capitalized like this: VERY!
Consider yourself warned :)

Thanks for reminding me that spotted dead nettles are VERY invasive. I actually like that because I hope this creeping perennials can be able to cover all my sideyard, then I don't need to worry about picking up weeds.

I'm going to disagree about this plant being very invasive. It's relative, Lamiastrum galeobdolon or yellow archangel, IS considered invasive and is listed on a number of state's invasive plants listings. However, while I'd consider lamium an aggressive spreader under the right conditions, it is NOT invasive and is quite easily removed from areas where you don't want it.

There is always a risk when unilaterally labelling a plant as "invasive". First, true invasiveness relates to a non-native plant's ability to colonize and overtake/overwhelm native species to the detriment of natural ecosystems. The term is not technically used to describe a plant's growth habit in a garden setting. Second, a plant's ability to spread aggressively or to become invasive relies very heavily on location - what has the potential for invasiveness in one area of the country will not necessarily be invasive everywhere else. Climate, hardiness zone and growing locations will play a very large role. Finally, good groundcovers are by definition spreaders - some more aggressive than others - but that is their nature and function. Doesn't make much sense to plant a groundcover that doesn't spread to some significant degree and cover the ground :-)

IME in my rather mild and often damp zone 8 climate and in a rich soil, partially shady location, spotted deadnettle (Lamium) is a very attractive and extremely manageable GC with NO invasive tendencies and only a moderately aggressive growing habit. YMMV

Yes, you are right, gardengal. I was loose with language. To me, the difference between invasive and aggressive is whether a plant resprouts and spreads again from small root pieces left in the ground after removal of the crown. You are right. Lamium doesn't do that. It does spread very quickly, which, as you note, is a good thing for a ground cover.

Supersweet, I would say that you're being optimistic about not needing to weed among this, or almost any other ground cover that I am acquainted with. Ground covers certainly do help shade out alot of weeds, and some do a good job of choking out most, but there always seem to be a few weeds that manage to come up anyway.

I wish mine would spread more! I have not found it to be invasive. I love the newer dark purple bloomed Lamium but mine is soft pink.

I just love to see everybody giving suggestions to my topic. Now, I have another question about how to plant the spotted deadnettle that I got from the forest. Actually, I picked them yesterday and tried to root them in a water bucket before I plant them on my sideyard sometime on Monday. However, some of them seem to be dying on me. My question is if I should root them at all? Or should I just plant them right on the ground after I pick them? Anyone has an answer for me????

Supersweet, you say you "picked" them. You need to dig them up, roots and all. (You probably know this, but just in case...) Get a piece out with a pretty good root system and soil around the roots, plant it and water it. As the stems get longer and run along the ground, they will root as they go along.