Oaks of the World

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  Quercus treubiana
Author Seemen 1906
Synonyms  
Local names  
Range Borneo (Sabah, ) ; Sumatra (Palembang) ; 600 to 2200 m;
Growth habit more than 20 metres tall; may reach 30 m, with trunk to 0.6 m in diameter;
Leaves 5-11 x 1-3 cm; thin but coriaceous; narrowly lanceolate; base attenuate, acute, sometimes asymmetrical; apex acute to acuminate; margine entire or remotely serrulate on apical half; hairless above;   pubescent beneath with minute simple hairs; 5-10 vein pairs distantly spaced, parallel, forming an angle of 45-60° with the midrib, prominent both sides; petiole 1-2 cm long, flat above, tomentose, glabrescent;
Flowers male catkins 3 cm, densely pubescent; male flowers 1 to 3, perianth 5-6-lobed, silky, 5-6 stamens, pistillode replaced by a tuft of stiff, simple hairs; female inflorescence 1.5-3 cm long, with 1-3 flowers;
Fruits acorn 2-3 cm long, 1-2 cm in diameter, shortly cylindrical, ovoid or subglobose, pubescent, apex depressed, base convex; enclosed 1/3 or 1/2 by cup; cupule halfround, pubescent, with 10-12 undulate concentric rings; fruiting in July-August;

Bark, twigs and
buds

bark fissured into rectangular plates; twigs initially densely pubescent with simple, brownish hairs, then glabrescent, with lenticels; terminal buds ovoid to ellipsoid; stipules linear, acute, deciduous, pubescent, 5-10 mm long;
Hardiness zone, habitat not hardy; tropical mountain forests;
Miscellaneous -- Sub-genus Cyclobalanopsis;
-- Section Semiserrata, sub-section Gemelliflorae (Menitsky).
-- A. Camus : n 87 ;
-- Melchior Treub, 18511910; former Director of the Bogor Botanic Gardens, Indonesia.
Subspecies and
varieties
 
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