Quercus helferiana is a tree up to 20 m. tall, with a trunk up to 0.3 m in diameter. Leaves oblong-elliptic, to elliptic-lanceolate, 120-150 (up to 220) × 40-80 (up to 95) mm, with wavy edges but no teeth or lobes. The
acorn is
oblate, 10-16 × 15–22 mm, grey, with a depressed apex and often covered with shaggy hairs; the scar is 12–14 mm in diameter, flat to concave at maturity. Flowering is in March–April, acorns found from October–November. ==References==