Quercus stenophylloides

Quercus stenophylloides, known as Arisan oak, is an evergreen broad-leaf tree endemic to Taiwan. It belongs to the Quercus subgenus Cerris, section Cyclobalanopsis. The species can grow up to 15 meters (49 ft) in height with trunks measuring up to 40 centimeters (16 in) wide. Its gray branchlets feature lenticels. The leaves vary from lanceolate to ovate-oblong, ranging in length from 6–14.5 cm (2.4–5.7 in) and width from 1.2–4.2 cm (0.5–1.7 in). They are acuminate at the apex and acute or obtuse at the base. The upper surface is green, while the underside is grayish-white or glaucous with hairiness. Leaves have a coriaceous texture, echinate-serrate margins, concave midribs above, and elevated midribs below. They feature 9–17 pairs of lateral veins and petioles measuring 1–2.3 cm (0.4–0.9 in). The tree is monoecious, with unisexual flowers blooming from May to June. Staminate catkins are about 5 cm (2 in) long, while individual staminate flowers are 3.5 mm (0.14 in) long. Each flower has 4–6 lobed perianths, hairy externally and glabrous internally, with 4–9 stamens. The filaments measure 2.5 mm (0.1 in), and the anthers are 1 mm (0.04 in). Pistillate flowers are smaller, at 2 mm (0.08 in) long and 3.5 mm (0.14 in) wide, with 3–4 lobed perianths and curved styles. The fruits mature from October to November. The cupules are 0.9–1.2 cm (0.4–0.5 in) long, 1.3–1.5 cm (0.5–0.6 in) wide, with 8–9 concentric rings and tomentose scales. Their margins are dentate-serrate, enclosing ellipsoid nuts measuring 1.7–2.1 cm (0.7–0.8 in) long ...