Reminds me of Hypericum gentianoides, is that a small orange/yellow flower on top of one?

No esh_ga, it has no flowers. The yellow speck is another weed, I think, but I like the little yellow flowers it produces so I'm less inclined to decimate it.

Do you know if the hypericum has a blackish looking stem? Also, when I try to pull it, I can't get the roots because the plant top snaps off so easily. That's what makes me think it must be some horrible weed :-)

Looks like Horse tail......terrible weed.............

I agree with horse tail ugh

What should I do? Dribble some 20% acetic acid on them? Any other thoughts?

Thanks,

Amna

Have to dig it out.....which is very difficult since its roots go down feet not inches!
Round up or other chemicals have no effect!
20% acetic acid will only burn the tops off and it will resprout and be back.....

Try a strong concentrated Roundup(~5%) on it. You can find concentrated Roundup in generic form in Walmart for instance.
Just look for the chemical Glyphosate in a high percentage, eg, 25%.