铜叶钟花杜鹃 tong ye zhong hua du juan

Rhododendron aeruginosum J. D. Hooker, Rhododendr. Sikkim-Himalaya 3: t. 22. 1851; R. campanulatum var. aeruginosum (J. D. Hooker) Cowan & Davidian.

Leaf blade 5–9 × 3–3.5 cm; abaxial surface rust-yellow, indumentum thick, felted; adaxial surface with metallic luster when young. Corolla lilac or purple. Fl. Jun.

Forests, thickets, alpine slopes; 3700–4300 m. S Xizang [Bhutan, Nepal, Sikkim].

It is probable that subsp. aeruginosum merits specific rank, as originally described. There is a form intermediate between R. aeruginosum and typical R. campanulatum in W Bhutan, E Nepal, and perhaps S Xizang that shares the glaucous leaves of R. aeruginosum but has pale flowers like those of R. campanulatum. The status of this entity requires further research.