I have a weed growing in my yard that is distinguished by its spindly seed stalks with individual seeds at the ends of branching fingerlets. It grows in distinct clumps. In the picture below, note the seed stalk to the lower left. Does anyone know what this is? Looking at other similar questions, this does not look to me like dallisgrass or annual bluegrass.
It's not Poa annua, Annual Bluegrass. I believe it might be Dichanthelium laxiflorum, a well-behaved native that pops up in disturbs sites. Soft Tuft Witchgrass.
My guess is Poa annua, annual bluegrass. Why do you think this is not a viable ID? Usually spread by birds. A favorite grass for golf courses. Shallow rooted, light green color, the seeds lighten this plant even more causing a larger contrast to the grasses in a lawn. Easiest way to deal with annual bluegrass is to water your garden and lawns deeply and make sure you allow the soil to dry out in between watering. The grasses with deeper roots by being forced to grow deeper to reach the moisture will be able to out compete the shallow rooted grasses as they are not able to find moisture. Allowing your grasses to never get shorter than 3" will curb any germination of Poa annua by shading the soil.