ID by Miri: "A weedy Crepis, probably vesicaria? Common name is Hawksbeard. Dan, have you ever considered submitting some of your pics to CalPhotos? You would make a lot of amateur botanists extremely happy with your close attention to detail and exact ID's." Thanks! Since C. vesicaria ssp. taraxacifolia is the only Crepis in the Jasper Ridge Plant List, I am going with that. You can tell from its looks and growth pattern (disturbed lands...) that it is an invader -- after the Spaniards came, that is. It grows near roads and paths in many parts of Jasper Ridge. Nice flower, though, and puffballs later. Road F near Escobar Gate.