Eriophyes? sp. Cecidium nov.
Small galls in the axils of the lateral veins of the leaflets. Above marked by a light colored angular area 1-1.5 mm dia. Below a small mass of tissue (the gall proper) fills the angle, covered by a fine close pubescence. Chamber within of small diameter, irregular in shape. The characteristic mites were definitely observed. They are white in color. On some leaflets every angle made by the midvein branching into the lateral ones was occupied by a gall. On H cordiformis, in Athens County Ohio, August.
”- Bertram Wells: (1915) A Survey of the Zoocecidia on Species of Hicoria Caused by Parasites Belonging to the Eriophyidae and the Itonididae (Cecidomyiidae)©
Reference: https://www.biodiversitylibrary.org/item/21732#page/49/mode/1up