奶桑 nai sang

Morus alba Linnaeus var. laevigata Wallich ex Bureau; M. laevigata Wallich ex Brandis; M. macroura var. mawu (Koidzumi) C. Y. Wu & Z. Y. Cao; M. wallichiana Koidzumi; M. wittiorum Handel-Mazzetti var. mawu Koidzumi.

Trees 7-12 m tall, d.b.h. 10-20 cm; dioecious. Branchlets pubescent when young. Winter buds ovoid-ellipsoid to ovoid, white pubescent. Stipules small. Petiole 2-4 cm; leaf blade ovate to broadly ovate, 5-15 × 5-9 cm, membranous, abaxially pale green and with short soft hairs along midvein and lateral veins when young, adaxially dark green and with soft hairs along veins, base rounded, ± cordate, or truncate, margin minutely and densely serrate, apex acuminate to shortly acuminate; secondary veins 4-6 on each side of midvein. Male catkins axillary, paired, 4-8 cm; peduncle 1-1.5 cm. Female inflorescences cylindric, 6-12 cm; peduncle 1-1.5 cm. Male flowers: calyx lobes ovate, adaxially pubescent; filament ca. 2.5 mm; anther globose. Female flowers: calyx lobes pubescent; ovary ovoid, declinate, ± compressed, pubescent; style absent; stigma 2-branched, papillate. Syncarp yellowish white when mature, 6-12 cm; achenes ovoid. Fl. Mar-Apr, fr. Apr-May.

Mountain forests, tropical forests; (300-)1000-1300(-2200) m. E Xizang, S Yunnan [Bhutan, Indochina, Malaysia, Myanmar, Sikkim, Thailand].

This species is used for paper making and the wood and leaves are used in dyeing.