I'd say a Vicia sp. But I cant differentiate them w/o a flower.

Some sort of vetch? Can you take a picture outside? And flowers? Is it woody? I don't see a seed pod in the second picture.

updated with seed pods. I will try and get a picture tomorrow morning.

It looks to me like crown vetch. Crown vetch has those kind of seed pods and leaves and grows in fields so it could easily invade an unkempt garden

Crown Vetch looks a good fit on the evidence so far. Securigera varia.

Thanks a lot guys. I looked up crown vetch and I think you are right. I have a lot of weeding to do over the next few months. I am going to try and get the vetch up before those seeds drop.

. I have a pretty large yard for the city but this yard has not seen care in years.

==>> john.. seriously dude ... hire a lawn service.. and spend the dough.. next year.. for them to eradicate it all.. and get you on the road to a fine lawn ...

you are not going to 'weed out' years of dropped seed ...

you need to basically.. grow the lawn so lush.. it chokes out.. and buries all the old seed ... while you kill all those that sprout next spring ...

you can do it with the famous brand 4 bag all season system ... for about the same cost the pro's will handle it for ...

once they get you going.. and you get your learning curve up ... you can do it all yourself ...

i know there is a hardcore lawn warrior forum ... if you want to go way over the top.. and do it yourself ...

ken