Since moving to NM we have discovered the world of sand spurs or grass spurs as some call them. This has to be one of the most evil weeds in existence.
This is how they sneakily appear in our lawn. They start out looking just like blades of grass before they break forth their spurs.
If you walk over them when dry they stick in the bottom of your shoes with their barbed thorns. You can walk on the cement and here them crunching under your feet but it does little to break them down.
The worst offense of these little evil doers is when they find their way into the house and get in the rugs or carpet. You will never forget the feeling of stepping on them with bare feet. The poor dogs find their share of them on walks as well. Limping starts and we have to stop and remove the offenders. Recently we hired a man to come spray our yard for them in a desperate attempt to end this torture. For weeks we were pulling them out by hand (with gloves of course).