环青冈 huan qing gang

Quercus annulata Smith in Rees, Cycl. 29: Quercus no. 22. 1814; Q. glauca Thunberg var. annulata (Smith) A. Camus.

Trees to 15 m tall. Branchlets grayish brown, sulcate and convex lenticellate, cylindric and dark gray by 2nd year. Leaf blade oblong-elliptic, elliptic, or ovate-lanceolate, 9-13 × 3.5-5 cm, abaxially whitish and veins grayish brown (whitish on tertiary veins) with prostrate simple hairs, adaxially smooth, base broadly cuneate to subrounded, margin awnlike serrate to sharply serrulate, apex acuminate to caudate; midvein and secondary veins adaxially impressed; secondary veins 10-14 on each side of midvein, often fusing at serration; tertiary veins abaxially prominent. Infructescences solitary, subapical on branchlet, 1-2 cm, 3-5-fruited. Cupule shallowly bowl-shaped, 6-8 mm × 1.2-1.5 cm, outside thinly grayish brown pubescent, inside grayish brown sericeous, wall ca. 1 mm thick; bracts in 7-9 rings, margin entire. Nut ovoid, 1.2-1.5 × 1.1-1.4 cm, loosely incanous; stigmas 3 or 4, often separated; scar 6-7 mm in diam., convex; stylopodium persistent, often basally 4-ringed. Fl. Mar-Apr, fr. Oct-Nov.

Broad-leaved evergreen forests in mountains. W Sichuan, E Xizang, W to SW Yunnan [Nepal]

The type is from Nepal, and specimens from the Himalayas as well as from Vietnam have sometimes been included under this name. This species is questionably distinct from Cyclobalanopsis glauca, and further studies may show that they are conspecific.