Debregeasia wallichiana (Wedd.) Wedd.

Shrubs or small trees to 6 m tall, monoecious; trunk to 8 cm d.b.h.; bark brown. Branchlets stout, leaf scars conspicuous, 3-4 mm, smooth; branchlets and petioles appressed pubescent. Leaves crowded at apex of branchlets; stipules large, oblong-lanceolate, 12-20 × 2.5-5 mm, 2-cleft at apex; petiole 3-15 cm; leaf blade adaxially dark green, broadly ovate to orbicular, 7-18 × 6-16 cm, thinly papery, 3-veined, lateral ones straight, reaching to middle, anastomosing with lowest of secondary veins 5-8 on each side from middle of leaf, abaxial surface thinly white tomentose, sparsely appressed pubescent on veins, adaxial surface subglabrous or sparsely appressed strigose, sometimes rugose, base broadly cuneate, rounded or cordate, margin sinuate-dentate, apex shortly caudate or shortly acuminate. Inflorescences borne on current and previous years’ branches, 3-7-dichotomously branched, 3.5-7.5 × 3-6.5 cm; peduncle 2.5-6.5 cm, spreading hirtellous; glomerules globose, 3-5 mm in diam.; bracts membranous, of male ones narrowly obovate to oblong-lanceolate, 0.5-0.8 mm, of female ones subcordate, 1-1.3 mm, densely pubescent abaxially. Male flowers shortly pedicellate, obovoid in bud 1 mm in diam.; perianth lobes 5, broadly ovate, glabrous abaxially, connate at the middle, apex acute; rudimentary ovary stipitate, obovoid, ca. 0.6 mm. Female flowers sessile, obovoid, ca. 0.7-0.8 mm; perianth tube membranous, 4-ribbed, 4-denticulate at apex. Achene ca. 1.3-1.5 mm, enclosed by membranous perianth but not adnate to it. Fl. May-Aug, fr. Jul-Sep.

S Yunnan (Mengla) [E Bangladesh, Bhutan, Cambodia, India, N Myanmar, Nepal, Sikkim, Sri Lanka, Thailand].

Subtropical Himalaya (Nepal to Bhutan), Khasia, Burma, Indo-China.

400-1200 m

Subtropical forests, slopes of limestone mountains; ca. 800 m.

Missiessya wallichiana Weddell, Ann. Sci. Nat., Bot., sér. 4: 195. 1854; Debregeasia ceylanica J. D. Hooker; D. leucophylla Weddell; Morocarpus ceylanicus (J. D. Hooker) Kuntze; M. wallichianus (Weddell) Blume.

Debregeasia wallichiana là loài thực vật có hoa trong họ Tầm ma. Loài này được (Wedd.) Wedd. mô tả khoa học đầu tiên năm 1857.

长序水麻（学名：Debregeasia wallichiana）为荨麻科水麻属下的一个种。