ouchies / sandspurs

There are these small spikey things in the grass around here sometimes. They hurt quite a bit, if you get them stuck in your skin... removing them is painful too, because if you try to pull one out with unprotected fingers, it usually embeds itself into your fingers.

Today, Serena got a couple of them stuck in her paw (I noticed her suddenly yelp in pain as she was running towards me), and I helped her get them out.

So, this evening, I was trying to find out what they are called. It seems they are called sandspurs or sandburs.

I also wanted to find out what these weeds look like while they are still young, so that I could uproot and dispose of them before they develop the painful burs. I sometimes see grass that looks like this around my yard, and wondered if that might be it. But even though someone labelled that photo "sandspurs", the burs on that grass are soft, and don't seem like they'll develop into the hard spikey painful ones I'm interested in. So I suspect that particular grass/weed is not really sandspur. I think this photo must be how it looks... but by the time it is at that stage, it is already dangerous.