Quercus engelmanni
Leaf galls, detachable
Truncated cone covered with spines, 6-7 mm high, erect on under side. Fig 173.
Fig 173. Unknown. On under side of leaf of Q engelmanni [sic]. Spines mostly weathered away and gall contained a pupa on March 6 (Descanso).
”- LH Weld: (1957) Cynipid Galls of the Pacific Slope©
Reference: https://babel.hathitrust.org/cgi/pt?id=coo.31924018313555&view=1up&seq=88