Filarees (Erodium moschatum), or storksbill, are those cool scissor-type weeds that you commonly find out in dry empty fields [not many of these left in California!]
okay, maybe they're not so cool if you're a dog and happen to snort one up your nose. This naturalized Mediterranean weed from the geranium family appears during the springtime in Davis, and bears small purple flowers with five petals. It is a free-seeding annual with a shallow taproot and hairy leaves forming a basal rosette.
It is the plant's fruit that most people recognize — those scissor-type things. Each fruit (schizocarp) is composed of five sections called carpels and a long, slender style column. When they begin to dry out, the mature carpels separate and as the styles uncoil, the carpels are forcibly ejected. Upon landing the style corkscrews the seed-bearing carpel into the soil. It's at about this point that the plant becomes hazardous to animals sniffing about the ground.