Old name is Zigadenus, Tom if you hsven't had anyone else post a correction. I don't know the species epithet but it could be paniculatus. Toxicoscordion paniculatum is the new name that will appear in the new Jepson Manual. This information is posted at Calphotos.
BTW great photos. I am doing a show on insects of the Yuba Pass area this Saturday in Tilden Park. I was checking to see if you had some IDs that fit my images. Bob Case
