Quercus Purpusi Trel. 1924

Twigs moderate (3-4 mm.), somewhat fluted, from tomentose glabrescent,
gray-buff with rather prominent small lenticels. Buds brown, glabrescent,
round-ovoid, 2 x 3 mm. Leaves deciduous, obovate, very obtuse, convallately
cordate often with closed sinus, undulate to somewhat crenate or serrate above
with mucronate veins, rather large (3-8 x 10-13 cm.), someČ what glossy and
glabrous or with granular midrib above, dull, yellow, and somewhat scurfy
beneath, the denuded surface low-bullate-granular; veins about 10-12 pairs,
somewhat branching but obscurely looped; petiole more or less tomentose,
2-3 x 5 mm. Catkins?. Fruit annual, solitary on glabrescent peduncles
2-3 x 25-90 mm.; cup half-round, large (25 mm. in diameter), with thick-based
appressed acute canescent scales; acorn oblong, half-included.
Mexican cordillera and adjacent Western Sierra Madre.