Oaks of the World

General data Classifications List of species Local names Back to
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  Quercus rex
Author Hemsl. in Hook. 1901
Synonyms Cyclobalanopsis rex (Hemsley) Schottky 1912
ructiseptata A. Camus 1934
Cyclobalanopsis fructiseptata (A. Camus) Hjelmq. 1968
dussaudii Hickel & A.Camus 1921
subumbilicata A.Camus 1935 (A. Camus : n° 71)
Local names da guo qing gang ;
Range Myanmar; Laos; S China (Yunnan); NE India (Assam, Arunachal Pradesh ) ; Vietnam ; 1100-1800 m;
Growth habit may reach 40 m; girth of the trunk to 3 m.
Leaves 12-27 cm x 4-9 cm; somewhat crowded at the end of the twigs; coriaceous; oblong-lanceolate, lanceolate or oblanceolate; apex acute to shortly acuminate; base cuneate; margin minutely serrate towards apical half; densely tawny tomentose when young; mature leaves shiny green and hairless above, hairless and glaucous beneath from more or less abundant waxy coat; 12-22 vein pairs, impressed or flat above, such as the midvein, raised below; tertiary veins evident below; petiole 1.8-2.4 cm long, thick, hairy;
Flowers April-May; male catkins in clusters of 3, thin, drooping; male flowers with perianth 5-lobed, 6 stamens with hairy anthers; female flowers 6-8 styles; 
Fruits very large acorn 3.5-5 cm in diameter, subglobose, depressed at apex, pale brown; enclosed 1/2 or 1/3 by cup; cup sessil, flat, 1.5-1.8 cm hight, 3.5-6 cm in diameter, 4 mm thick, tomentose, with 6-9 concentric rings marginally entire or sinuate; basal scar 2-2.5 cm in diameter, impressed; stylopodium often deciduous; maturing in 1 or 2 years;

Bark, twigs and
buds

bark grey reddish brown; twigs slender, pale brown tomentose at first, becoming hairless, with many lenticels; deciduous, straight, 2.7 cm long stipules;
Hardiness zone, habitat not hardy; dense forests in valleys;
Miscellaneous -- A. Camus : n° 60;
-- Sub-genus Cyclobalanopsis;
-- Section Helferiana, sub-section Helferianae (Menitsky);
-- Endangered in China;
-- Flora of China n° 24;
Subspecies and
varieties
 
Pictures

drawing 1
drawing 2