光柱迷人杜鹃 guang zhu mi ren du juan

Rhododendron pennivenium I. B. Balfour & Forrest, Notes Roy. Bot. Gard. Edinburgh 13: 55. 1920; R. tanastylum I. B. Balfour & Kingdon Ward var. pennivenium (I. B. Balfour & Forrest) D. F. Chamberlain.

Leaf blade narrow, oblong-elliptic to broadly lanceolate, 2.5–3.5 cm wide; base cuneate; apex acute to acuminate; corolla lobes 5; filaments glabrous; ovary densely tomentose and sparsely glandular-hairy; style glabrous. Fl. Mar–Apr.

Mixed forests, broad-leaved forests; 2400–3300 m. W Yunnan [NE Myanmar].

It is possible that var. pennivenium is a variety of Rhododendron tanastylum, not of R. agastum as given in FRPS (57(2): 130. 1994) and here. The leaf indumentum does not indicate a close relationship with R. agastum.