21. Argyreia formosana Ishigami ex T. Yamazaki, J. Jap. Bot. 44: 160. 1969.
台湾银背藤 tai wan yin bei teng
Ipomoea tomentosa Yamamoto.
Climbers woody, with ± yellowish pubescent axial parts. Stems striate; young parts densely sericeous, later glabrescent. Petiole 1.5-8 cm; leaf blade broadly ovate-cordate, 6-11 X 5-9 cm, abaxially densely yellowish white sericeous-tomentose, adaxially glabrous, base shallowly cordate to ± truncate, apex acute to acuminate; lateral veins 7-12 pairs, prominent abaxially. Inflorescences axillary, cymose, 4-6-flowered; peduncle 1.5-2 cm; bracts early deciduous, ovate, 4-6 mm. Pedicel 6-8 mm. Sepals ovate-oblong, slightly concave, subequal, 6-8 X 3-5 mm, densely sericeous abaxially, glabrous adaxially, apex rounded to obtuse. Corolla deeply 5-lobed; tube ca. 5 mm; lobes oblong, reflexed, 1.3-1.5 cm, densely pilose outside, glabrous inside. Stamens and pistil exserted; filaments ca. 1 cm; anthers 3-4 mm. Ovary ovoid, glabrous, 2-loculed. Style filiform, ca. 1.5 cm; stigma 2-lobed. Fruit reddish, globose. Seeds 4 or fewer, ovoid-trigonous. Fl. Oct, fr. Jan.
* Forests. S Taiwan (Kaohsiung, Pingtung Xian, "Ape's Hill")
Argyreia formosana was not treated in Fl. Reipubl. Popularis Sin. and was considered a synonym of A. obtusifolia Loureiro in the Flora of Taiwan (4: 348. 1978). Loureiro's name has been widely misapplied to various taxa in China and throughout southeast Asia, and the protologue is so vague that it is impossible to apply the name correctly. The Taiwanese specimens are quite distinct from all taxa called A. obtusifolia from mainland China and southeast Asia, and the prudent course seems to be to recognize them under Yamazaki's name until a careful study can be undertaken.