It is Bahia, I can tell because in the photos you can see the black V seed heads. I will guess you live below the mason Dixon line or if in Cali, south of SF. I just reread your post, your in FL. This is an OK low maintenance grass. No need to fertilize, but if you do, it will grow fast and need to mow twice a week. If you leave the seed heads on for over 2 months they will become viable seeds. You can use 2,4-d as a herbicde. Metsulferon will kill it, along with many other herbicdes. I would suggest to self install an irrigation system. Then decide what kind of grass you want. Many people in florida have Bahia for lawns. If you keep this as your lawn, I will suggest that you mow it high, 2-3 inches as this type of grass is an open grower. The lower you mow, the more sun gets to the soil, the more weeds you have. My house had this when I moved in, I installed irrigation, killed off the lawn with round up and plugged an empire zoysia lawn. I would suggest that if you do not like yard and lawn work, keep the bahia, if not, I would look into bermuda (princess or riveria), zoysia, and last, if you have no traffic in your yard (dogs or kids) and you like the spongy feel go with SA.

I'm guessing you are in the UK. In which case it is Carex pendula. A native but a self seeder and can be a nuisance. Not a disaster in that position but it will send babies out around the garden. Any herbicide will need to be specific for grass/sedge, not a broad leaf weed killer.

One looks like Tall fescue, and the other Dallis grass. The Dallis grass( and other weeds in the picture) can be killed with 'Bayer advanced all in one'. The Tall fescue has to be sprayed with 'Round up' the resulting dead spot re-seeded a couple weeks later.

Hello all... I have Tall Fescue here in MN, but we also get "Clump Grass" or clumps of course fescue, normally used on road sides( Kentucky 31 Fescue is a coarse fescue that is often sold for roadside plantings) and such.. Course or "BAD" fescue will grow in clumps in your KBG and /or Tall fescue lawn, the only way to get rid of it is... If you only have a little of it, you can dig it out, but its going to have a rather large root system, you can try and spot spray Round Up on each clump, but you may kill some surrounding desirable grass also... If you have lots of it all over, it may be best to start over. Again, depends have truly bad it is... I also dont think Alligare Chlorosulfuron 75 will kill Tall Fescue.. The herbicide is a selective herbicide, I have never used it, but I looked it up and I didnt see where that would kill what your trying to kill... Have a great day!