思茅银背藤 si mao yin bei teng

Lettsomia maymyo W. W. Smith, Rec. Bot. Surv. India 6: 38. 1914.

Climbers woody; axial parts ± yellowish pilose, later glabrescent. Stems terete. Petiole 6-9.5 cm; leaf blade broadly ovate-cordate, 10-16 X 10.5-13 cm, ± sparsely strigose, base shallowly cordate, apex abruptly acuminate. Inflorescences ± umbellate, 7-15-flowered; peduncle 15-22 cm; bracts early deciduous, attached near middle of pedicel, linear, ca. 5 mm. Pedicel 1-2 cm. Sepals ovate-oblong, unequal; outer 3 4-5 X ca. 2 mm; inner 2 larger, ± yellowish sericeous abaxially, glabrous adaxially, apex obtuse to rounded. Corolla purple, funnelform, flaring strongly from base, 4-5.5 cm; limb entire to shallowly lobed, midpetaline bands densely whitish sericeous-pilose, otherwise glabrous. Stamens and pistil included; filaments 2-2.5 cm, glandular basally; anthers oblong, 5-6 mm. Pistil capitate, 2-globose; ovary ovoid, glabrous. Style 2.6-3 cm. Fruit ellipsoid, 1-1.4 cm, projecting from persistent (but not enlarged) sepals. Fl. Oct.

* Mountain forests; 1500-1800 m. Yunnan (Simao) [N Myanmar]

Argyreia maymyo was not recognized in the Fl. Reipubl. Popularis Sin. account. An examination of Chinese material called in that account A. roxburghii (Wallich) Arnott var. ampla (Wallich) C. B. Clarke reveals that A. maymyo and A. mastersii (Prain) Raizada (as defined here) were included. The two species are readily separated by the ligulate bracts which are lacking in A. maymyo and so prominent in A. mastersii.