Oaks of the World

General dataClassificationsList of speciesLocal namesBack to
home page

  Quercus urbanii

Trel. 1924 Proc. Amer. Philos. Soc. 60: 32
Diagnosis here


pennivenia Trel. 1924 Diagnosis here
conzattii Trel. 1921 Proc. Amer. Philos. Soc. 60: 33

Local names encino cucharillo;
Range Mexico in the South of the Sierra Madre Occidental (Guerrero, Durango, Jalisco, Nayarit, Mexico, Sonora, Zacatecas); 1500 - 2500 m ;
Growth habit 6-12 m tall, with trunk to 0.3 m in diameter or more; thick branches very tomentose;
Leaves 14-30 cm; deciduous; almost orbicular, oboval, oval-elliptic or panduriform; stiff; convex; reticulate epidermis adaxially ; apex rounded; base narrowly cordate; margin thick, revolute, cartilaginous, entire or wavy-dentate with 5-20 pairs of small aristate teeth at apical 2/3; adaxially pale green, lustrous, rough, glabrous except simple glandular hairs and stellate ones on veins; densely yellowish tomentose beneath with stalked stellate trichomes on the whole surface of the blade, trichomes with rayed to 3 mm long; 9-11 vein pairs, sinuous or curved, seldom straight; epidermis papillose and glandular; petiole 2-4 cm long, tomentose; young leaves conspicuously red and hairy;
Flowers in December-January; male catkins 10-20 cm long, with pubescent axis and numerous flowers; pistillate flowers on 4-5 cm long tomentose racemes;
Fruits acorn 8-10 mm long, ovoid; 6 to 10 together on a yellow tomentose stalk reaching 9 cm long; small cup, half-round, enclosing 1/3 or 1/2 of nut; maturing in 1 year, in October;

Bark, twigs and

twigs 6-10 mm thick, yellow grey tomentose during several years, with inconspicuous lenticels; buds 5-10 mm long, ovoid, brown; stipules persistent around terminal buds, 7 mm long;
Hardiness zone, habitat not hardy; poor calcareous soils;
Miscellaneous -- A. Camus : n° 311;
-- Sub-genus Quercus, section Lobatae, Subsection Erythromexicanae, Group Racemiflorae;

Subspecies and
-- Q. conzattii Trel. 1921 Proc. Amer. Philos. Soc. 60: 33 Diagnosis here
= Q. urbanii f. parvifolia Martinez 1954
Many Authors consider it as a true species. However it is different from Q. urbanii only in having all its parts smaller, leaves never panduriform, and some other minor features...See Q. conzattii.

-- The northern occurrence of Q. urbanii, (sensu Spellenberg & Bacon 1996), corresponding to a separate genetic lineage for McCauley & al. (2020), can be ascribed to Q. pennivenia.