This is one of the many unassuming plants that will be leaving souvenirs in your socks throughout the summer. With seed pods studded with hooked barbs, it catches easily on fabric and fur. Hedge parsley, or Torilis arvensis, is a mildly invasive species that has spread throughout much of the state (below 5,249 feet according to CalFlora, though such a precise number seems a tad arbitrary).
With tiny white flowers and only a few small leaves scattered along the stem, this calf-high plant is easily missed–though its burrs are more noticeable. Hedge parsley is in the large and diverse carrot family (or Apiaceae), landing on the untasty end of the spectrum that ranges from poison hemlock to culinary parsley.