698 



Ericaceae 



4. Rhododendron parvifolium Adams. R. palustre 

 Turcz. ex DC. Sakai-tsutsuji. Mostly erect, much- 

 branched evergreen shrub to 1 m. high, densely clothed with 

 sessile discoid scales, the branchlets slender, puberulous; leaves 

 somewhat coriaceous, narrowly elliptic or lanceolate-oblong, 

 1-2 cm. long, obtuse to subacute, abruptly acute at base, gla- 

 brous, sometimes brownish beneath, the midrib impressed on 

 upper side, the petioles 1-3 mm. long; flowers 2-5, 1.5-2 cm. 

 across, rose-purple, the pedicels 3-5 mm. long in fruit; calyx- 

 lobes broadly ovate, 1-1.5 mm. long, obtuse; corolla glabrous, 

 infundibuliform; stamens 10; style glabrous; capsules ovoid- 

 oblong, 5-6 mm. long, about 3 mm. across. Wet places in 



lowlands; Hokkaido (near Nemuro) ; rare. Sakhalin, Ko- 

 rea, and e. Siberia. 



5. Rhododendron brachycarpum D. Don. R. jauriei 

 Franch.; R. brachycarpum var. lutescens Koidz.; R. jauriei 

 var. lutescens (Koidz.) Takeda; R. brachycarpum var. rosae- 



florum Miyoshi Hakusan-shakunage. Evergreen shrub 



1-3 m. high, the young branchlets sometimes soft brown- 

 pubescent; leaves somewhat coriaceous, narrowly oblong, 6-15 

 cm. long, 2-5 cm. wide, obtuse to rounded, mucronate, 

 rounded to shallowly cordate at base, entire, slightly recurved 

 on margins, glabrous, deep green on upper side, paler beneath, 

 the petioles often reddish, 1-1.5 cm. long; inflorescence 5- to 

 15-flowered, on a very short axis, the pedicels brown-pubes- 

 cent, the bracts and bud-scales deciduous; calyx very small; 

 corolla white or pinkish, pale green spotted on inside of upper 

 lobe, glabrous, infundibuliform, 3-4 cm. across; stamens 10, the 

 filaments loosely white-puberulent on lower half; ovary rusty- 

 pubescent; style 1-1.5 cm. long, glabrous, ascending; capsules 

 short-cylindric, becoming glabrous at maturity, 1-1.7 cm. long, 



5-6 mm. in diameter. June-July. Coniferous woods in 



mountains; Hokkaido, Honshu (centr. and n. distr.). 



Forma nemotoanum Makino. R. brachycarpum var. nemoto- 



anum (Makino) Nakai ^Nemoto-shakunage. Stamens 



petaloid. Honshu. 



Var. roseum Koidz. R. brachycarpum var. roseum (Ma- 

 kino) Nakai; R. jauriei var. rufescens Nakai Shieobana- 



SHAKUNAGE. Leavcs beneath with dense, short, pale brown 

 hairs. Occurs with the typical phase. 



6. Rhododendron metternichii Sieb. & Zucc. Hymen- 

 anthes japonica Bl.; R. metternichii var. heptamerum Maxim. 



TsuKUSHi-sHAKUNAGE. Large evergreen shrub to 4 m. 



high, with thick terete branches rusty-tomentose while young; 

 leaves coriaceous, oblanceolate, 8-20 cm. long, 2.5-5 cm. wide, 

 acute at both ends, deep green, lustrous, entire, with slightly 

 recurved margins, densely rusty-tomentose beneath, the peti- 

 oles 1-2 cm. long; inflorescence many-flowered, sessile, the 

 bracts and bud-scales deciduous, the pedicels 2-5 cm. long, 

 rusty-pubescent while young; corolla infundibuliform, 4-5 cm. 

 across, 7-lobed, rose-colored, glabrous; stamens 14, the fila- 

 ments white granular-pubescent on the lower half; ovary 

 densely rusty-villous; styles glabrous, 3-3.5 cm. long; capsules 

 ovoid-cylindric, 15-25 mm. long, 7-8 mm. in diameter, with 

 persistent brown hairs. ^May-June. Dense woods in moun- 

 tains; Honshu (w. Shinano and westw.), Shikoku, Kyushu. 



Var. hondoense Nakai. Hon-shakunage. Tomentum 

 on the under side of leaves, appressed, thinner and paler. Oc- 

 curs with the typical phase. 



Var. pentamerum Maxim. R. degronianum Carr.; R. pen- 



tamerum (Maxim.) Matsum. & Nakai Shakunage, Azuma- 



SHAKUNAGE. Shrub to 2 m. high; leaves oblanceolate to ob- 

 long-lanceolate, 8-15 cm. long, obtuse, acute at base, with pale 



brown tomentum beneath; flowers 5-merous, 3-4 cm. across; 

 styles glabrous, 2.5-3 cm. long; capsules short-cylindric, 1.5-2 



cm. long, 5-7 mm. in diameter. May-June. Woods in high 



mountains; Honshu (centr. and n. distr.). 

 Var. yakushimanum (Nakai) Ohwi. R. ya\ushimanum 



Nakai Yakushima-shakunage. Tomentum more dense 



on leaves beneath, on the pedicels, and on the ovary; flowers 

 5-merous. High mountains; Kyushu (Yakushima). 



7. Rhododendron makinoi Tagg. R. metternichii var. 

 pentamerum forma angustifolium Makino; R. stenophyllum 

 Makino, non Hook, f.; R. metternichii var. angustifolium 



(Makino) Bean Hosoba-shakunage. Erect evergreen 



shrub with thick, brown-pubescent branchlets, the bud-scales 

 remaining on the branches for several years; leaves coriaceous, 

 lustrous, deep green, linear-oblanceolate, 10-15 cm. long, 1-2 

 cm. wide, acute at both ends, with slightly impressed veinlets 

 on upper side, thickly brown-tomentose beneath, the petioles 

 1-2 cm. long; inflorescence rather many-flowered, the bud- 

 scales persistent at base, the pedicels brown-villous; calyx very 

 small; corolla pale rose-colored, 3-4 cm. across, infundibuli- 

 form, 5-lobed; stamens 10; ovary brown-villous; style glabrous, 

 about 3 cm. long; capsules oblong, brown-pubescent. ^Moun- 

 tains; Honshu (Totomi and Mikawa Prov.). 



8. Rhododendron aureum Georgi. R. chrysanthum 



Pall.; R. officinale Salisb. ^Kibana-shakunage. Prostrate 



evergreen shrub, the branches thick, minutely puberulent 

 while young or nearly glabrous, the bud-scales persistent; leaves 

 thick-coriaceous, glabrous, deep green, slightly paler beneath, 

 obovate-oblong, obovate, or oblong, 3-4 (-6.5) cm. long, 1.5-2 

 (-2.5) cm. wide, rounded to very obtuse, slightly cuneate and 

 acute to obtuse at base, veinlets impressed above, the petioles 

 1-1.5 cm. long; inflorescence 3- to 10-flowered, sessile, terminal, 

 the pedicels 2.5-5 cm. long, brown-pubescent; calyx very small; 

 corolla 2.5-3.5 cm. across, pale greenish yellow, glabrous; sta- 

 mens 10, puberulous toward the base of filaments; ovary 

 brown-pubescent; style 1.5-2 cm. long, glabrous, longer than 



the stamens; capsules narrowly oblong, 1-1.5 cm. long. 



July-Aug. Alpine slopes; Hokkaido, Honshu (centr. and n. 



distr.); rare. n. Korea, Kuriles, Sakhalin, Kamchatka, and 



e. Siberia. Forma senanense (Yabe) Hara. R. chrysan- 

 thum forma senanense Yabe Yae-kibana-shakunage. The 



stamens petaloid. Honshu (centr. and n. distr.). 



Rhododendron X nikomontanum Nakai. Nikk6-ki- 

 bana-shakunage. Hybrid of R. aureum X R. brachycarpum. 



9. Rhododendron semibarbatum Maxim. Azaleastrum 

 semibarbatum (Maxim.) Makino Baika-tsutsuji. De- 

 ciduous shrub about 2 m. high, the young branches slender, 

 erect or ascending, white-puberulous and glandular-pilose; 

 leaves membranous, fasciculate and terminal on the branchlets, 

 elliptic to narrowly so, 3-6 cm. long, 1.5-2.5 cm. wide, acute, 

 rounded to obtuse, or sometimes subacute at base, serrulate, 

 green on upper side, often glaucous beneath, the midrib white- 

 puberulent on both sides and loosely glandular-pilose beneath, 

 the petioles 5-10 mm. long, glandular-pilose; flowers about 1.5 

 cm. across, white, suffused rose-purple, the pedicels white- 

 puberulous and glandular-pilose, 5-10 mm. long; calyx with 

 5 short lobes, glandular-pilose; corolla short-tubular, 5-lobed; 

 stamens unequal in length, the 2 upper filaments shorter and 

 densely white-pubescent throughout, the 3 lower stamens with 

 longer glabrous exserted filaments; styles glabrous; capsules 



globose, glandular-pilose, about 5 mm. across. ^June-July. 



Thickets in mountains; Honshu, Shikoku, Kyushu. 



