Quercus ariifolia Trel.

Mexico, in the Sierra Madre Oriental (Hidalgo, Nuevo León, Puebla, Queretaro, San Luis Potosi and Veracruz); 1900-2890 m;

7-15 (-20) m ;

6-12 cm x 3-7; coriaceous; elliptic to elliptic-oblong, rarely ovate; usually flat abaxially, seldom convex; apex obtuse; base rounded to subcordate; margin revolute, with 2-4 pairs of mucronate teeth in apical half; adaxially dark gree, rugose, glabrous or with fasciculate hairs scattered along midrib; abaxially tomentose, made of light chestnut or whitish fasciculate trichomes, with long crispate rays, and rarely with glandular trichomes; 7-11 veins pairs, ascending, straight or mederately curved, impressed above, prominent beneath; epidermis bullate and papillose; petiole 0.6-1 cm tomentose to glabrescent, with fasciate trichomes;

in May;

acorn ovoid to globose, light brown, 1-1.5 cm long, 1 to 2 or more together on a 2-7 cm long pubescent peduncle; included 1/4 to 1/2 in the cup; cup halfround somewhat shallowy, 1.2-1,4 cm high and to 2 cm in diameter, with margin erect, and smooth triangular scales; maturing first year in September and October;

– Sub-Genus Quercus, Section Quercus, Série Leucomexicanae, Group Reticulatae; – This taxon was considered in the past as a synonym of Q. rugosa ; – “Quercus ariifolia can be confused with Q. rugosa and Q. greggii . However it can be distinguished by its whitish-lanuginous abaxial blade surface and because it generally lacks amber glandular trichomes, while Q. rugosa and Q. greggii always have abundant amber glandular trichomes on the abaxial blade surface. Additionally the leaves of Q. rugosa are usually concave abaxially, while those of Q. ariifolia are not. Quercus greggii can be distinguished by its coriaceous-rigid leaves and the yellowish-tomentose abaxial blade surface. Q. ariifolia was proposed as a synonym of Q. rugosa (Muller 1997, Nixon & Muller 1997, Valencia-A. 2004, Valencia & Flores-Franco 2006), but there are differences such as those above described, that allow us to recognize these as two distinct species.” S. Valencia-A. 2017