Quercus stenophylloides, also called Arisan oak, is a species of evergreen, broad-leaf tree endemic to Taiwan. It is placed in Quercus subgenus Cerris, section Cyclobalanopsis.[1]
Quercus stenophylloides can grow up to 15 m(49 ft) tall, with trunks up to 40 cm(16 in) wide. They have gray branchlets with lenticels.[2]
Leaf shape can range from lanceolate to ovate-oblong, 6 - 14.5 cm(2.4 - 5.7 in) long, 1.2 - 4.2 cm(0.5 - 1.7 in) wide, acuminate at apex, and acute or obtuse at base.
They are green on the upside, grayish-white, glaucous or green and hairy beneath.
The texture is coriaceous. Echinate-serrate on the edge. Midribs are concave above, elevated beneath. Lateral veins 9 - 17 pairs. Petioles 1 - 2.3 cm(0.4 - 0.9 in) long.
Blooming from May to June, the flowers are unisexual and are both small, hairy, growing on the same individual tree.
Both are arranged on a stem, only staminate flowers' are a lot longer. Also, staminate flowers are arranged spirally on a slim drooping stem — this is called catkins.
Staminate catkins are about 5 cm(2 in) long; Staminate flowers are about 3.5 mm(0.14 in) long; 4 - 6 perianths, lobed, hairy outside, glabrous inside; 4 - 9 stamens, filaments 2.5 mm(0.1 in) long, anthers 1 mm(0.04 in) long.
Pistillate flowers are 2 mm(0.08 in) long, and 3.5 mm(0.14 in) wide; 3 - 4 perianths, lobed, hairy, 3 - 4 styles, curved.
Fruits mature from October to November. They are first green, then brown and fall to the ground when mature. The cupules are 0.9 - 1.2 cm(0.4 - 0.5 in) long, 1.3 - 1.5 cm(0.5 - 0.6 in) across, scales in 8 - 9 concentric rings, tomentose, margins of rim dentate-serrate; nuts ellipsoid, 1.7 - 2.1 cm(0.7 - 0.8 in) long, 1.2–1.6 cm(0.5 - 0.6 in) across.
They are commonly seen in mountains at the altitude of 900 – 2600 m throughout the Taiwan island.