Quercus sororia Liebm.

Mexico (Durango, Guerrero, Jalisco, Mexico, Michoacan, Morelos, Nayarit, Oaxaca, Sinaloa) ; 1000-2300 m ;

4.4-15 x 1.2-4.6 cm; lanceolate, elliptic or more often oblong; hairless; glaucous; margin entire, or remotely lobed or crenate;

acorn solitary, stalkless, with thick cup wall; cupscales at the base have a thickened base, and acute loosely appressed apex;

– Often considered as a synonym of Q. peduncularis, but S. Valencia and A. Coombes 2019 think it is a true species.