Oh dear Hank, they are horsetails, aka mares tail. The roots can go down extremely deep which is why there's always some left. Is this the first year you've seen them? They can even puncture membrane and are very difficult to get rid of.

https://www.rhs.org.uk/advice/profile?PID=257

Yes, it's the first time I've seen them ( I think ) i had something a bit different in the past which I thought were horsetails but these are different. I tried to dig some out with a fork/ spade and found the origin at least a foot deep.
When things are finished this year I'll have a really good go at them. I pull up / break off about 15 more every day.

They are different because they are probably the fertile fronds which appear early in the season. If left they will develop a swelling that looks like a bud at the top, and this will release lots of spores that will spread the blessing everywhere around. The others will probably pop up later...
Bear in mind that the roots can go down a lot deeper than you can dig - its being so cheerful that keeps me going.

Thanks for that Sue, quite made my day ! So I suppose the only thing I can do is go out every morning and pulling them up, or breaking them at ground level. So be it.

Hi Hank, I'm afraid Steragram is right, they are horsetails, Equisetum arvense, and are VERY difficult to get rid of, you can use glyphosate weedkiller, but you will have to bruise the stems first, because they have a waxy coating on them, and the weedkiller just runs off, and you will have to give them several treatments, but pulling them up as soon as you see them does help, try and get them up before the spores develop, best of luck, Derek.

Hi Hank, I'm afraid Steragram is right, they are horsetails, Equisetum arvense, and are VERY difficult to get rid of, you can use glyphosate weedkiller, but you will have to bruise the stems first, because they have a waxy coating on them, and the weedkiller just runs off, and you will have to give them several treatments, but pulling them up as soon as you see them does help, try and get them up before the spores develop, best of luck, Derek.

Sympathy Hank - you can't win 'em all but you can have a good try...