Description from Flora of China
Magnolia yunnanensis (Hu) Nooteboom.
Trees, to 30 m tall, to 50 cm d.b.h., andro-dioecious. Bark grayish white, smooth and not fissured. Petiole 1-2.5 cm; leaf blade ovate-oblong to ovate-elliptic, 6.5-15(-20) × 2-5 cm, thinly leathery, abaxially pale green and adaxially green but both surfaces purplish red when young, secondary veins 7-15 on each side of midvein, reticulate veins conspicuous on both surfaces, base broadly cuneate to nearly rounded, apex shortly acuminate to acuminate. Flowers fragrant. Male flower: tepals 12, in 4 whorls; outer tepals red, obovate, ca. 4 × 2 cm; tepals of inner 3 whorls white, narrowly obovate-spoon-shaped, 3-3.5 cm, fleshy, base tapering into claw; stamens ca. 30, ca. 2.5 cm; filaments ca. 1 cm, red; connective exserted and forming a ca. 1 mm mucro; anthers ca. 1.5 cm; torus rounded at apex. Bisexual flower: tepals as those of male flowers; stamens fewer than those of male; gynoecium green, ovoid. Fruit long ovoid, ca. 6 cm; mature carpels rhombic, dehiscing along dorsal sutures when matured. Seeds compressed, 6-7 × ca. 10 cm; testa red. Fl. May, fr. Sep-Oct. 2n = 114.
Evergreen broad-leaved forests; 1200-1500 m. SE Xizang, Yunnan [N Myanmar].