Ericaceae 697 



24B. Young branches with apprcsstd nonglandular hairs and spreading, somewhat glandular-tipped hairs. 



26A. Stamens 5; ovary glandular-pilose 2i. R. macrosepalum 



26B. Stamens 10; ovary strigose 24. R. ripensc 



13B. Branchlcts glabrous or pilose; leaves fully deciduous, mostly fasciculate at ends of branchlcts. 

 27A. Leaves in 3's, terminal on the branchlcts. 



28A. Ovary short glandular-pubescent, sometimes eglandular on the upper part. 



29A. Stamens 5; leaves glandular-dotted, glabrous or sparingly pubescent on upper side 25. i?. dilatatum 



29B. Stamens 10; leaves while young with long straight hairs. 



30A. Leaves broadly rhombic; petioles glandular-pilose; young branchlcts glabrous 26. R. decandrum 



30B. Leaves ovate, acute; petioles with long eglandular hairs; young branchlcts hairy 27. R. viscistylum 



28B. Ovary densely hirsute, the hairs eglandular. 



31A. Flowers usually after the leaves, red to deep rose; stamens nearly equal in length. 



32A. Leaves lustreless; petioles with loose coarse hairs, the pedicels with coarse hairs only on the lower portion; 



flowers red, before or with the leaves, April and May 28. R. weyrichii 



32B. Leaves lustrous; pedicels, petioles, and capsules appressed woolly-pubescent; flowers after the leaves. May to 

 July. 



33A. Flowers deep rose. May and June; pedicels 5-8 mm. long 29. R. sanctum 



33B. Flowers red, July; pedicels 6-13 mm. long 30. R. amagianum 



3 IB. Flowers usually before the leaves, rose-purple; stamens unequal in length. 

 34A. Petioles glabrous at least on the lower part. 



35A. Pedicels and calyx densely pilose; leaves glabrous beneath 31. i?. mayebarae 



35B. Pedicels glabrous on upper part or loosely pilose; leaves with white appresscd-hairs beneath while young. 

 36A. Midrib of leaves beneath glabrous or short pilose; capsules thickly cylindric, 4-5 mm. across. 



32. R. /(^iyosiimensc 

 36B. Midrib of leaves beneath densely barbate near the base; capsules slenderly cylindric, 2-3 mm. across. 



33. R. nudipes 

 34B. Petioles pilose throughout. 



37A. Petioles, pedicels, and young branchlcts appressed-pubescent; midrib of leaves beneath glabrous or glabres- 



cent; capsules ovoid, 7-10 mm. in diameter 34. R. reliculatum 



37B. Petioles and basal part of leaf midrib beneath densely long-pubescent. 



38A. St)le with short glandular hairs on lower half; capsules short-cylindric 35. R. wadanum 



38B. Style glabrous; capsules ovoid-cylindric 36. R. lagopus 



27B. Leaves in 5's, verticillate, terminal on the branchlcts; flowers white 37. R. quinqtiejoUum 



12B. Flowers from a terminal bud, the vegetative shoots lateral. 

 39A. Leaves in 5's, terminal on the branchlcts, elliptic, 2.5-4.5 cm. long; branchlcts quite glabrous; flowers 1 or 2, deep 



rose-colored; ovary glabrous 38. R. pentaphyllum 



39B. Leaves alternate, the upper ones more or less approximate, oblanccolate to obovate, 5-10 cm. long; branchlcts coarsely 

 pilose while young; flowers 2-8; ovary densely pilose. 



40A. Flowers rose-purple; stamens 10 39. R, albrechtii 



40B. Flowers orange-yellow, sometimes vermilion, or clear yellow; stamens 5 40. iJ. japonicum 



9B. Flowers in loose erect racemes on leafy shoots of current growth; bracts parually persistent 41. /?. camtschatkiim 



1. Rhododendron keiskei Miq. R. \eis\ei var. cordi- obtuse to subacute, acute at base, with dense sessile discoid 



]olium Masam. Hikage-tsutsuji. Evergreen shrub to brownish scales beneath, the petioles 2-5 mm. long; flowers 



abou 1 m. high, with yellow discoid sessile scales; leaves some- rose-purple, solitary, the pedicels short, covered by the bud 



what coriaceous, lanceolate to broadly so, or rarely narrowly scales at anthesis, 6-8 mm. long in fruit; calyx small, with 5 



oblong, 4-8 cm. long, 1.2-2 cm. wide, abruptly acute to shal- undulate teeth; corolla broadly infundibuliform, about 3 cm. 



lowly cordate at base, mosdy glabrous, often puberulous on the across, scattered puberulent outside; stamens 10, the filaments 



upper side near base, sparsely scaly beneadi, entire, the margin white-pubescent at the base; styles glabrous; capsules cylindric, 



slighdy recurved, the petioles 2-6 mm. long; flowers 2-5, nearly scaly, about 1 cm. long, 2.5-3 mm. across. May. Hok- 



umbellate, pale greenish yellow, the pedicels 1-1.5 cm. long; kaido. Korea, n. China, and e. Siberia. 



calyx small, with 5 undulate teeth; corolla 5-lobed, infundi- 3. Rhododendron mucronulatum Turcz. R. daurkum 



buliform, 2.5-3 cm. across, with discoid sessile scales outside; var. mucronulatum (Turcz.) Maxim. Kara-murasaki-tsu- 



stamens 10, the filaments slightly pilose near base; style gla- tsuji. Deciduous shrub 1-2 m. high, with sessile discoid 



brous; capsules cylindric, 1-1.2 cm. long, 2.5-3 mm. across, scales throughout and often coarse hairy; leaves somewhat 



Apr.-May. Rocky wooded slopes in mountains; Hon- coriaceous, narrowly elliptic to broadly lanceolate, 3-7 cm. 



shu (Kanto Distr. and westw.), Shikoku, Kyushu. long, 1.2-2.5 cm. wide, pale green beneath, acute to acuminate 



Var. hypoglaucum Suto & Suzuki. Urajiro-hikage-tsu- at both ends, sometimes glabrous, the petioles 3-10 mm. long; 



Tsuji. Leaves obovate-oblong, usually slightly glaucous be- flowers solitary, before the leaves, broadly infundibuliform, 



neath, with sessile discoid scales on both surfaces while young, 4-5 cm. across, rose-purple, the pedicels 5-10 mm. long; calyx 



persistent only beneath; corolla puberulent outside, scarcely small, 5-toothed; corolla loosely pubescent outside; stamens 10, 



scaly. May. Honshu (Mount Ozaku in Shimotsuke); rare. the filaments white-pubescent at the base; style glabrous; cap- 



2. Rhododendron dauricum L. Ezo-murasaki-tsu- sules cylindric, 1-1.5 cm. long, 3-4 mm. across. Apr. Hon- 



Tsuji, Tokiwa-genkai. Partly evergreen branched shrub, shu (Chugoku Distr.), Kyushu (n. distr.). Korea, China, 



the branchlcts with sessile discoid scales; leaves rather cori- and Ussuri. 



aceous, oblong to ovate-oblong, 2.5-4 cm. long, 1-1.5 cm. wide, 



