圆基火麻树 yuan ji huo ma shu

Laportea basirotunda C. Y. Wu, Acta Phytotax. Sin. 6: 276. 1957.

Small trees, 5-7 m tall, 20-40 cm d.b.h., branchlets semiwoody; bark gray-green, sometimes purplish, lenticels elliptic; upper stem and branchlets appressed pubescent, soon glabrescent. Stipules caducous, broadly ovate, ca. 0.6-0.8 cm, leathery, densely puberulent abaxially; petiole 4-11 cm, sparsely appressed pubescent and armed with short stinging hairs; leaf blade dark green, broadly ovate or broadly elliptic, 11-22 × 7-16 cm, papery, 3-veined, lateral veins 5-8 each side, anastomosing before margin, tertiary veins subparallel, adaxial surface sparsely strigose or subglabrous, abaxial surface pubescent and sparsely armed stinging hairs on veins, base rounded or subcordate, margin entire or inconspicuously remotely serrulate, apex acuminate; cystoliths minutely punctiform, conspicuous adaxially. Inflorescences in distal axils of branchlets, long paniculate, slightly longer than petioles. Male flowers sessile, in bud 1.2 mm; perianth lobes 5, ovate, pubescent; stamens 5; rudimentary ovary obovoid, 0.4 mm. Female flowers 3 or 4 in a row on slightly fleshy flabellate peduncular receptacle, subsessile, ca. 1 mm; perianth lobes 4, unequal, 1 large, ca. 1 mm, 2 medium ca. 0.5 mm, ventral small, ca. 0.2 mm. Ovary ca. 1 mm; stigma straight, ligulate, ca. 2 mm; bracts ca. 0.3 mm. Achene orbicular-ovoid, oblique, compressed, ca. 2.5 mm, conspicuously verrucose; persistent perianth forming a minute cupule at base. Fl. Aug-Sep, fr. Sep-Oct.

Mixed forests on limestone; 1000-1200 m. S Yunnan [Myanmar, Thailand].