Please help me ID this prickly weed.
I've been gardening here 38 years and never saw this weed until now. We buried our inground pool and planted a vegetable garden on the spot, and this weed showed up.
The plant is a couple of feet tall, a collection of angular stems growing in every direction. Here are closeups of the tip and stem. Those thornlike projections aren't visible to the naked eye (at least not mine), but you quickly learn not to get too close to this weed.
Thanks for your help!