Fl. des Serres 9: 77 (1854)
Verified by:
Shrub, 1-3 m; young shoots densely covered with adpressed flattened red-brown strigose hairs. Leaves dimorphic, persistent, chartaceous; spring leaves lanceolate to elliptic, 2-4(-5) x 1-2.5cm, 1.7-2.3 x as long as broad, apex acute or obtuse, base cuneate, margin entire, strigose on both surfaces, especially on midrib; summer leaves 10-20 x 5-1 Omm, otherwise as for spring leaves; petioles 3~-5mm, indumentum as for young shoots. Inflorescence 2-3-flowered; pedicels 3-5mm, densely covered with adpressed brown strigose hairs. Calyx 3-5mm, strigose, lobes divided to base, ovate-orbicular. Corolla funnel-shaped, 20-30mm, red (in cultivated forms from pink to salmon-red); tube 10-15mm, glabrous. Stamens 5(-6), longer than corolla, filaments papillate in lower half. Ovary densely red-brown strigose; style glabrous. Capsule c.5mm long, setose.
Japan (C Hokkaido to Yakushima)
Mixed deciduous forest
Tsutsusi’Kaempfer, Amoen. Exot. Fasc. 845, t.846 (1712)ó basionym, (Sloane Hb 211:8, 62, BM). Azalea kaempferi (Pianchon) Andre, Belgique Hort. 15: 184 (1865); Rhododendron indicum (L.) Sweet var. kaempferi (Planchon) Maxim., Rhododendr. As. Orient. 38 (1870); R. scabrum G. Don var. kaempferi (Planchon) Nakai, Bot. Mag. (Tokyo) 33:208(1919). Rhododendron sieboldii Miquel, Ann. Bot. Mus. Lugduno-Batavum 1: 33 (1863). Described from Japan. R. kaempferi Planchon var. macrogemma Nakai, Trees, Shrubs Japan ed. 1: 103 (1922); R. macrogemma (Nakai) Nakai, Bot. Mag. (Tokyo) 45: 128 (1931). Type: Japan, Idzu Prov, Oshima, nearSenzu, Okubo, n.v.
Chamberlain, D.F. & Rae, S.J. (1990) A Revision of Rhododendron IV Subgenus Tsutsusi. Edinburgh Journal of Botany 47(2):120