22. Boehmeria siamensis Craib, Bull. Misc. Inform. Kew. 1916: 269. 1916.
八棱麻 ba leng ma
Boehmeria chiangmaiensis Yahara; B. spirei Gagnepain.
Shrubs or small trees, simple or branched distally, 1-3 m tall, to 1.5 cm in diam.; upper stems, branches, and petioles sparsely or densely strigose. Dioecious or monoecious. Buds ovoid, 2-5 mm; scales triangular-ovate. Leaves opposite, subequal in size; stipules lanceolate, 7-10 mm; petiole 0.3-1.2 cm; leaf blade light green when dry, narrowly ovate, elliptic, or rarely oblong, 5-15 × 2-8 cm, thickly papery, secondary veins 3 or 4 each side of midvein, abaxial surface with reticulate vein prominent, both surfaces sparsely appressed strigose, base subcordate or rounded, slightly oblique, margin serrulate, apex acuminate or shortly acuminate. Glomerules on axillary, densely congested, spikelike shoots, simple in distal part of twigs or in groups of 2 or more in axils of fallen leaves; male ones in lower axils, 4-6 cm; female ones in distal axils; bracts scarious, ovate, ca. 3 mm. Male flowers 4-merous, sessile; perianth lobes elliptic, 1.8-2 mm, densely puberulent, connate to middle; rudimentary ovule obovoid, ca. 0.4 mm. Fruiting perianth tube fusiform or narrowly rhomboid-obovoid, compressed, 1.8-2 mm, patent puberulent all over, base cuneate, apex long necked, 2- or 3-toothed. Fl. Mar-Apr, fr. Sep-Oct.
Secondary forests, sunny thickets; 400-1800 m. W Guangxi, S Guizhou, S Yunnan [Laos, Myanmar, Thailand, Vietnam].
The fibers are used to make ropes.