G. Don, Gen, Syst. 3: 846 (1834)
Verified by:
Shrub or small tree, l-8m; young shoots soon glabrous. Leaves rhombic-ovate, 3-6 x 1.5-4cm, apex acute, upper surface at first covered with short hairs, soon becoming glabrous, lower surface with short brown hairs, mainly on midrib and veins; petioles 2-5mm, covered with brown bristle-like hairs. Inflorescence l-2(-3)-flowered, flowers appearing before the leaves; pedicels 5-8mm covered with adpressed brown hairs, glandular, Calyx minute, ciliate, villous, glandular. Corolla funnel-campanulate, rose-purple, rarely white, 25-30mm, lobes 15mm, oblong. Stamens 10, unequal, filaments glabrous. Ovary villous; style glabrous (? occasionally pubescent below). Capsule 10mm, curved.
Japan (S Honshu, Shikoku, Kyushyu)
Forest hillsides
R. rhombicumMiq., Ann. Mus. Lugduno-Batavum2: 164(1865). Type: A specimen collected by Buerger, n.v. R. rhombicum Miq. var. albiflorum Makino, Bot. Mag. (Toyko) 18: 66(1904). Type: Fl. white; Prov.Zyodaizi-yama in Sakawa spont., iv 1885, T. Makino. R. sakawanum Makino, J. Jap. Bot. 3:11 (1926). Type: as for R. rhombicum var. albiflorum Makino. R. reticulatum D. Don var. bifolium Yamazaki, J. Jap. Bot. 62: 288 (1987). Type: Japan, Shikoku, Tokoshima Pref., Oshima, Mugisho, K. Abe 35670 (holo. TI, n.v.). R. reticulatum D, Don var. parvifolium Yamazaki, J. Jap. Bot. 59: 209 (1984). Type; Japan, Shikoku, Pref. Kohchi, Takaoka- gun, Hidaka-mura, Nishikiyama, 21 x 1942, Yashinaga 24 (holo. TI, n.v.)
Chamberlain, D.F. & Rae, S.J. (1990) A Revision of Rhododendron IV Subgenus Tsutsusi. Edinburgh Journal of Botany 47(2):148