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

3. Rhododendron subsect. Grandia (Tagg) Sleumer, Bot. Jahrb. Syst. 74: 549. 1949.

大叶杜鹃亚组 da ye du juan ya zu

Hu Linzhen (胡琳贞 Hu Ling-cheng); David F. Chamberlain

Rhododendron ser. Grandia Tagg in J. B. Stevenson, Sp. Rhodod. 305. 1930 ["Grande"]; Waldemaria Klotzsch.

Trees or small trees, rarely large shrubs; young shoots stout, mostly ± tomentose. Leaf blade large, up to 70 cm, leathery or thickly leathery, oblong-elliptic to oblanceolate or obovate; abaxial surface with a 1- or 2-layered indumentum; adaxial surface glabrous when mature, usually plastered, compacted and agglutinated, rarely loose and felted indumentum. Inflorescence terminal, broad and large, 12–30-flowered; rachis stout, 10–60 mm. Calyx minute, 5–8-lobed; corolla broadly campanulate or ventricose-campanulate, rarely funnelform, (5–)6–8-lobed, fleshy, creamy-white, rose or deep purple-red, often with crimson basal blotch, with or without nectar pouches; stamens 10–20; ovary 6–20-locular, tomentose, glandular or glabrous. Capsule large, woody.

Twelve species: Asia; ten species (five endemic) in China.

1 Petiole flattened and winged, 0.5–2.5 cm. (2)

+ Petiole ± cylindric, 1.5–5 cm. (3)

2 (1) Petiole 1.5–2.5 cm; corolla obliquely campanulate, pale yellow to pink; ovary hairy. 244 Rhododendron praestans

+ Petiole 0.5–1 cm; corolla broadly campanulate, white to pink; ovary glabrous. 245 Rhododendron watsonii

3 (1) Abaxial leaf surface with loose, not agglutinated, indumentum. 242 Rhododendron protistum

+ Abaxial leaf surface with thin agglutinated indumentum. (4)

4 (3) Indumentum pale brown, tomentose, sometimes forming a marginal band.

+ Indumentum gray-white, 2-layered; upper layer arachnoid-tomentose, with a tendency to disappear. 243 Rhododendron magnificum

5 Vegetative bud scales persistent; flowers pink. 240 Rhododendron pudorosum

+ Vegetative bud scales deciduous; flowers crimson, pink, white, cream or yellow. (6)

6 (5) Corolla 5-lobed, crimson; stamens 10; leaf blade 12–17 cm. 241 Rhododendron oreogenum

+ Corolla 6- or 8-lobed, pink or cream to yellow; stamens 14–20. (7)

7 (6) Corolla pink; filaments glabrous. 239 Rhododendron montroseanum

+ Corolla cream to yellow; filaments hairy. (8)

8 (7) Pedicel and ovary tomentose and glandular; leaf blade 14–30 cm. 236 Rhododendron grande

+ Pedicel and ovary tomentose but not glandular; leaf blade 9–70 cm. (9)

9 (8) Leaf blade 20–70 cm; petiole 3–5 cm. 237 Rhododendron sinogrande

+ Leaf blade 9–21 cm; petiole 1.5–2.5 cm. 238 Rhododendron sidereum

Lower Taxa