Quercus helferiana A.DC.

India; Laos; Thailand; Vietnam; Myanmar; China (Guangdong, Guangxi, South Guizhou, South Yunnan); 900 to 2000 m;

reaches 20 m tall, but often stunted in exposed sites; trunk reaches 1 m in circumference;

12-20 x 4-9 cm; evergreen; sub-elliptic or oval-lanceolate; young leaves densely tomentose; apex acuminate to obtuse, base rounded or broadly cuneate; margin crenate in the apical half; adaxially smooth, shiny, glabrous except at the base of the midrib; grey brown tomentose beneath, with persistent fasciate hairs; midvein impressed adaxially; 9-14 vein pairs, raised below, slightly impressed above ; stout petiole 1-2(-3) cm long, pale brown tomentose, glabrescent;

March-April; female on many-flowered spikes as long as the petiole; 5-6 short styles, staminodes sometimes present;

acorn flattened 1-1.6 cm long, 1.5-2.2 cm wide; mucronate; flat or sometimes depressed, 1.2-1.4 cm wide basal scar ; enclosed 1/2 by cup; cup flat (5-6 mm long, 2-2.5 cm wide) and thick (1.2-2 mm), with 8-10 concentric rings of minutely, golden tomentose scales, remotely denticulate; maturing in 1 year;

not hardy; tropical forests;

– A. Camus : tome 1, p. 336, n° 68; – Sub-genus Cerris, Section Cyclobalanopsis; – Section Helferiana, sub-section Helferianae ( Menitsky );