Quercus xylina Sheidw.

Mexico (Durango, Guanajuato, Hidalgo, Jalisco, Queretaro, Sinaloa); 1650-3000 m;

3-10 m tall;

6-8 x 3-5 cm; deciduous; coriaceous; thick; oboval or oblong; apex obtuse (sometimes acute), mucronate; base rounded or cordate, sometimes asymmetrical; margin thick, slightly revolute, crenate or with 3-6 mucronate teeth each side on the distal half of the blade; adaxially olive green, slightly rugose, glabrous or covered with scarce stellate and glandular trichomes; abaxially paler, densely and persistently tomentose (fascicled and glandular trichomes); 7-12 vein pairs impressed above, prominent beneath; epidermis white-papillose; petiole 7-13 mm long, tomentose at first, glabrescent;

flowering in May; male catkins 3 cm, with numerous flowers; female ones 5-10 mm long, with 1-5 pubescent flowers;

acorn 1.5-2 cm long, ovoid to oblong, glabrous; 1 to 8 together on a 4-10 cm long pubescent peduncle; cup less than 2 cm wide, with appressed scales, covering 1/2 of nut; maturing the same year in September and October

hardy

– A. Camus : n° 226 ; – Sub-genus Quercus, Section Quercus, Series Leucomexicanae; – The word xylina comes from the Latin “xylinus” which means “like cotton” in reference to the dense tomentum of the underside of the young leaves. – Closely related to Q.obtusata , which has subcoriaceous blades, the leaves are wider than in Q. xylina and have scarce fasciculate sessile trichomes on the abaxial surface. Possible confusion with Q. praeco , but this species has an acorn-cup rolled inside and the veins are not impressed adaxially. Resembles as well Q. deserticola which differs in having stellate trichomes abaxially. (See all differences HERE )