Keteleeria evelyniana, first described by Masters in 1903 is commonly known as the Yunnan you shan in the Chinese language and Du sam or May hinh in Vietnamese.
Description. Keteleeria evelyniana is an evergreen coniferous tree in the Pinaceae family which grows to 120 feet (40 m) tall. Its bark is grayish brown, irregularly and longitudinally fissured, flaking. Branchlets reddish or brownish red, turning brown, usually initially pubescent, glabrous in 2nd or 3rd year. Leaves narrowly linear, slightly falcate, 1.6 2.6 inches (4 - 6.5 cm) long, with stomatal lines. The seed cones are cylindrical, 3.5 to 8 inches (9 - 20 cm) long by 1.5 to 2.5 inches (4 - 6.5 cm) wide. Seed scales at middle of cones rhombic-ovate, 1.5 inches (3 - 4 cm) long by 1.1 inches (2.5 - 3 cm) wide, exposed part of abaxial surface pubescent or nearly glabrous. The seeds are oblong, one-half inch (0.9 - 1.4 cm) by 0.24 inch (5 - 7 mm); wing yellowish brown, semitrullate. Pollination occurs from April to May with seed maturing in October.
Distribution. This species is native to Laos, Vietnam (as far south as the Plateau of Langbian near Dalat), and China - western Sichuan, Yunnan (where it probably intergrades with K. davidiana), and W Guizhou; at 2,200 to 10,000 feet (700 - 2,900 m) elevation.
It grows in northwestern Vietnam at elevations above 2,000 feet (600 m) and is shade intolerant as it prefers neutral or limestone soils and is typically associated with Pinus spp. or with species of Fagaceace and Lauraceae, in some places being the dominant species.
