Oaks of the World

General data Classifications List of species Local names Back to
home page

  Quercus xylina
Author

Sheidw. 1837 Hort. Belge 4:321. 1837. pl. 18

Diagnosis here
Synonyms laxa Liebm. 1854
callosa Mart. ex A.DC 1864
reticulata var. laxa (Liebm.) Wenz. 1884
Local names
Range Mexico (Durango, Guanajuato, Hidalgo, Jalisco, Queretaro, Sinaloa); 1650-3000 m;
Growth habit 3-10 m tall;
Leaves 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;
Flowers flowering in May; male catkins 3 cm, with numerous flowers; female ones 5-10 mm long, with 1-5 pubescent flowers;
Fruits 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

Bark, twigs and
buds

grey, scaly bark; twigs yellowish, 3-4 mm thick, densely tomentose at first, then glabrescent; buds globose, ovoid, rarely conic, 2-3 mm long, with marginally hairy scales; stipules persistent at least one year; lenticels visible only the second year;
Hardiness zone, habitat hardy
Miscellaneous

-- 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)
Subspecies and
varieties
Pictures