From what I understand about winter annuals, they don't do well in thick turf. So in addition to possibly bringing up some weed seeds I left little pockets where the sun, air and light could easily get to germinate those seeds. I read somewhere that a 30 year old speedwell seed had successfully germinated. Scary. I really hate this weed. When I first noticed it I thought I had little christmas trees growing in my lawn. In the past, the only weed I had to deal with was clover and some other things here and there. Now that I'm actually trying to pay more attention to the lawn I'm seeing all sorts of weeds. On the plus side, all that squatting to pull weeds is good for the quads.

Motherwort, Leonurus cardiaca. Medicinal herb, great bumble bee plant, and a very sort-lived perennial (mostly biennial in nature). They pull out easily. Cut off spent flowers before they set seed to prevent more self-sowing. FataMorgana

Knowing your location would be helpful. Also, a picture of one of the runners on a plain background would be good. From the fuzzy picture a couple of shots in the dark to compare to are nimblewill, Muhlenbergia shreberi or torpedo grass, Panicum repens.

It's difficult for me to determine what I need to see because of the very busy background. Is it possible to dig out the plant and isolate it on the sidewalk or other plain background?