Rhododendron subsect. Falconera in Flora of China @ efloras.org

4. Rhododendron subsect. Falconera (Tagg) Sleumer, Bot. Jahrb. Syst. 74: 549. 1949.

杯毛杜鹃亚组 bei mao du juan ya zu

Fang Mingyuan (方明渊); David F. Chamberlain

Rhododendron ser. Falconera Tagg in J. B. Stevenson, Sp. Rhodod. 235. 1930 ["Falconeri"].

Shrubs or small trees, 3–10 m tall; young shoots stout, mostly ± tomentose, usually glabrescent. Leaf blade large, leathery, ovate to obovate-elliptic; abaxial surface with whitish, brownish or rufous 1- to 2-layered indumentum, the upper layer usually cup-shaped, the lower layer (when present) thin, sometimes compacted; adaxial surface glabrous. Inflorescence a racemose umbel, 12–20(–30)-flowered. Calyx minute, 1–3 mm; corolla tubular, funnelform to ventricose or obliquely campanulate, (5–)7–8-lobed, white, pale yellow or pink, less often magenta to purple, usually with crimson basal blotch; stamens (10–)12–18; ovary tomentose, glandular or glabrous (R. galactinum). Capsule cylindric.

Eleven species: Bhutan, China, India, Myanmar, Nepal, Sikkim, Vietnam; ten species (four endemic) in China.

1 Petiole flattened, winged. (2)

+ Petiole terete, not winged. (4)

2 (1) Leaf base narrow, cuneate, abaxial surface with agglutinated, patchy indumentum. 246 Rhododendron rothschildii

+ Leaf base subcordate, abaxial surface with indumentum not agglutinated. (3)

3 (2) Inflorescence rachis stout, 3.5–5.5 cm; corolla yellow. 248 Rhododendron basilicum

+ Inflorescence rachis 2–3 cm; corolla pink or white. 247 Rhododendron semnoides

4 (1) Ovary glabrous. 252 Rhododendron galactinum

+ Ovary densely tomentose. (5)

5 (4) Abaxial leaf surface with thin silver-gray or brownish indumentum; corolla pink or rose-purple. 254 Rhododendron hodgsonii

+ Abaxial leaf surface with dense grayish or brown indumentum; corolla yellowish or white to pink. (6)

6 (5) Leaf blade obovate or obovate-elliptic, abaxial surface with rufous brown indumentum. (7)

+ Leaf blade elliptic or oblong-elliptic, abaxial surface with whitish to mid brown indumentum. (8)

7 (6) Leaf blade 6–13 cm wide, abaxial cup-shaped hairs wide with shallowly fimbriate margin. 249 Rhododendron rex

+ Leaf blade 4–8 cm wide, abaxial cup-shaped hairs narrow with deeply fimbriate margin. 250 Rhododendron arizelum

8 (6) Leaf blade 11–16 cm wide, abaxial surface with dense pale gray-brown soft and spongy indumentum. 255 Rhododendron sinofalconeri

+ Leaf blade 4–13 cm wide, abaxial surface with brownish indumentum; the upper layer loose. (9)

9 (8) Corolla creamy yellow, 6–7-lobed, abaxial leaf surface with cup-shaped hairs deeply fimbriate. 251 Rhododendron preptum

+ Corolla pink or white, 5–8-lobed; abaxial leaf surface with cup-shaped hairs entire or moderately fimbriate. (10)

10 (9) Leaf blade 6–13 cm wide, abaxial surface with thick indumentum, cup-shaped hairs fimbriate; corolla 7–8-lobed. 249 Rhododendron rex

+ Leaf blade 4–7 cm wide, abaxial surface with thin indumentum, cup-shaped hairs not fimbriate; corolla 5–7-lobed. 253 Rhododendron coriaceum

Lower Taxa