Aylax hypochaeridis
Hypochaeris radiata
Fusiform swelling of midrib and peduncle. Widely distributed in western Oregon and Washington where it helps to check the spread of its introduced host plant. Galls have ben seen at OR-CA state line and in San Diego CA.
- LH Weld: (1957) Cynipid Galls of the Pacific Slope©
Reference: https://babel.hathitrust.org/cgi/pt?id=coo.31924018313555&view=1up&seq=70&skin=2021