56 THE AZALEAS OF THE OLD WOELD 



Lake Towada, June 25, 1894, U. Faurie (No. 13,279, Herb. Kew); 

 Hakkoda-san, alt. 1600 m. July 5, 1914, E. H. Wilson (No. 7122); 

 same locality, U. Faurie (No. 875, Herb. Kew). Hokkaido, prov. 

 Oshima, Esashi, August 4, 1890, K. Miyabe & Y. Tokubuchi (Herb. 

 Gray); prov. Ishikari, near Sapporo, September 17, 1892, C. S. Sar- 

 gent; Masuzan, July 30, 1897, U. Faurie (No. 636). 



Korea : prov. South Keisho, Chiri-san, peak Ten-no-bo, alt. 1845 m. 

 November 16, 1917, E. H. Wilson (No. 9595); same place, July 30, 

 1913, T. Nakai. 



Cultivated : Arnold Arboretum (No. 3691); Royal Gardens, Kew, 

 July 1, 1910; Gardens, Tokyo, May 31, 1882, K. Miyabe. 



This is an alpine or subalpine species that grows on most of the high mountains 

 in Hondo from Shinano northward; in Hokkaido it grows sparingly as far north 

 as the mountains round Sapporo. From Shikoku I have seen but one specimen 

 and it is not reported from Kyushu. Out of Japan this species has been found only 

 on the Chiri-san range in south Korea. This is an interesting discovery for the 

 plant does not grow on Quelpaert Island where so many Japanese species are 

 common, neither has it been found elsewhere in Korea. In the Nikko region R. 

 Tschonoskii is quite common, especially round Lake Yumoto, where it grows 

 on shady rocks. On Adzuma-san it is abundant in places fully exposed to the sun 

 and this locality is about the centre of its distribution. On the wind-swept upper- 

 slopes of Hayachine-san it is common but north of this mountain I found it to 

 be rare. 



The plant forms a broad, densely branched twiggy shrub from 0.3 to 2.5 m. 

 high but is usually from 0.5 to 1.5 m. being taller in the forest shade than on 

 exposed rocks. It prefers rocky ground, but seems to be equally happy in the 

 moist woods of Nikko and on the exposed cliffs and slopes of Adzuma and Haya- 

 chine mountains. Sometimes it forms a broad low mat but is more usually an 

 upright shrub. It is always very twiggy and the young shoots are densely cov- 

 ered with closely appressed, flattened rufous hairs. The short stalked leaves are 

 deciduous, crowded at the end of the branches, and vary in shape from narrow- 

 lanceolate to ovate-lanceolate or broad-oblanceolate, they are acute and mucronu- 

 late and may have one or three prominent nerves; the undersurface is pale and 

 both surfaces have long, appressed, soft, red-brown hairs which are especially 

 noticeable on the young leaves. The flowers are small, with a white corolla, and 

 are four or five partite; they have exserted stamens, and are borne in terminal 

 clusters of from 4 to 6 flowers in each. Except that the leaves vary in size and 

 may have either one or three prominent nerves, and that the flowers are tetram- 

 erous or pentamerous the species is very constant. From one and the same bush 

 on Adzuma-san I gathered specimens which exhibited the whole range of varia- 

 tion on which Makino founded his numerous forms. With its small white flowers 

 R. Tschonoskii is very distinct from all other Japanese species but as a garden 

 plant it has little to recommend it though in autumn the leaves change to rich 

 shades of orange-red and crimson. 



It was discovered in 1865 by Maximowicz's Japanese collector Tschonoski on 

 the mountains of Rikuchu province, northern Hondo, and is figured and described 

 by Maximowicz. It was introduced into England by Charles Maries who sent 

 seeds to Messers Veitch in 1878; to this country it was introduced by Professor 

 Sargent who sent seeds from the Nikko region to the Arnold Arboretum in 1892. 



