Vasilis Teodoridis:
5. Rhododendron subsect. Triflora (Hutchinson) Sleumer; Bot. Jahrb. Syst. 74: 536. 1949.
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67. Rhododendron siderophyllum Franchet; J. Bot. (Morot) 12: 262. 1898.
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Rhododendron ioanthum I. B. Balfour; R. jahandiezii H. Léveillé; R. leucandrum H. Léveillé; R. obscurum Franchet ex I. B. Balfour (1922); R. rubropunctatum H. Léveillé & Vaniot (1911); not Hayata (1913); nor T. L. Ming (1984).
Shrubs; 1–2(–4) m tall; young shoots brown; densely scaly. Petiole 5–15 mm; densely scaly; leaf blade elliptic or elliptic-lanceolate; 3–7(–11) x 1.2–3.5 cm; base cuneate or rounded; apex acuminate; acute or nearly obtuse; abaxial surface scales 0.5–2 x their own diameter apart; or contiguous small to mid-sized; all similar or slightly unequal; brown; concave; adaxial surface scales dense; concave; glabrous or rarely pubescent along midrib. Inflorescence terminal or subterminal; shortly racemose; 3–5-flowered; rachis 2–4 mm. Pedicel 0.3–1.3 cm; scaly; calyx rimlike or undulate and 5-lobed; densely scaly; co-rolla tubular funnelform-campanulate; white; pale red; pale pur-ple or rosy red; inside with yellowish green; pale red or pinkish spots or without spots; 1.6–3 cm; outer surface not scaly or sparsely scaly on lobes; stamens unequal; long ones longer than corolla; filaments pubescent or nearly glabrous at base; ovary 5-locular; densely scaly; style longer than corolla; usually gla-brous; rarely pubescent at base. Capsule cylindric; 11–16 mm. Fl. Mar–Jun.
? Mixed forests; coniferous forests on slopes; thickets; (1200–) 1800–3000 m. Guizhou; Sichuan; Yunnan.