I think it would have to be KY 62 Fescue - the old one from the late '50s that was so highly touted by the agricultural experts of that time as the best pasture grass for the midwest. Drought, too much rain, heat, cold, etc. resistant, good protein & fiber content, all types of livestock like it, makes good hay, etc. What they didn't know at the time is that once it grows into clumps as it often does over time, it can only be killed off by digging it up and making sure you get all the thousands of roots present, often develops toxins including oxypitocin, the one needed to induce labor resulting in abortions and fescue foot. Meaning the blood supply to the extremities is greatly reduced so the feet, ears, tails, etc. die and fall off shortly after birth. It also causes dairy cattle to dry up, and both dairy and beef cows can lose both teats and part or all of the udder. It was sown over hundreds of thousands of pasture land before they knew the downfalls of it. Even now it is still allowed to go to seed and the seeds harvested and sold as such. As far as I know no one has to report the type of fescue the seed is from when they sell it. Many new landowners wouldn't know if asked which type fescue the seed came from. It selfsows readily so it is invasive too. Since much of our yarden use to be pasture land on which said grass was sown, it is 95% or more it. Oh yes, it is also resistant to most grass & weed killers. I've waged war on it for nearly 30 years and it is still 75% victorious.It chokes out even 'ditch' dayliliies so not many domesticated plant families stand a chance against its invasive abilities.
And chickweed, both wide leaf and buckhorn plantain, wild ground ivy(looks like geraniums you raise in the house), sticktights, wild parsnip(I'm somewhat victorious in those last 2 wars), and some other invasive wild plants. Lots of pokeweed, Rose of Sharon, orange Trumpet Vine, Multifloral rose,perennial Sweet Pea, escasped domestic garlic that went to seed dispite Skyler's best efforts last year, etc. In spite of all that, we do have a very colorful yarden with lots of very welcome plants.
We also seem to have developed a sizeable population of snakes. Mostly black rat snakes. Kyle took one out of the utility room a few weeks ago and I just shot on in the bird house a few minutes ago. I didn't know they hunted at night so it was a definate GOD thing that I found this one tonight. I was looking for a mother hen and her 5 or 6 babies. Turns out the ducks were all standing guard over and around her. However it was headed for and only about 2' away from the other mother hen who had over a doz. babies when we counted them about 5 days after they hatched. I think we should count baby chicks again in the morning. The snake doesn't appear to have eaten recently.
Our old Beagle, Darcy, and the 2 newly aquired hunters, Dottie and Lady Di had a young ground hog more or less trapped in one of the flower beds this evening. Sheila saw it before it got into the bed so she knew what they had. Darcy stayed with the pursuit until she heard me coming. I had been in the house with no shoes on when Sheila came in with the report so I still had to get on my shoes. I sent her out with the gun with instructions to kill it if I don't get there in time. I did but only by seconds. Dottie, who is a 4 yr. old Rat Terrier/Chiauiaha(?)cross kept going back into the bed and I finally saw her keeping something more or less pinned down, and Lady Di who is a 3 - 4 month old Cavalier King Charles spaniel had been harrassing it out in the lawn when Sheila first saw and heard the commotion. As young as Di is, she knows no fear of anything. Sheila said she was jumping at the g.hogs face and snapping at it when she went over there to investigate. She said the g.hog was growling and charging her tormentors but they weren't backing off until she showed up with the gun. Then it was all up to Dottie.
She stayed right 'on point' so to speak until I had shot it and she was certain it wasn't going anywhere. Lots of "Good girl"s were handed out for that nice bit of work. Dottie may have had a headache and ringing ears for a good while as the gun was only a foot or so from her head when I shot. Sheila didn't know g.hogs are strict vegatarians so was afraid it was trying to have at least Lady Di for supper. It could have seriously injured her with those rodent teeth if it had gotten ahold of her in self defense.She only weighs about 3# at the most.
Ok, enough of my rambling. GOD bless and keep each of you.
I sprinkle cayenne pepper on the plants to keep them from eating my plants. Of course, I have to sprinkle the cay. pepper after it rains each time. 
