1925] WILSON, THE RHODODExNDRONS OF EASTERN CHINA 157 



a remarkable affinity with that of western China, General accounts 

 of these floras I published in volumes I. and II. of the Arnold Arboretum 

 Journal (1919-20). 



The flora of eastern China in the main is distinct from that of western 

 China, the province of Hupeh being a sort of hinterland between the 

 two regions. The flora of Hongkong and neighboring islands was once 

 supposed to be rich in endemic plants but many of these have since been 

 found on the mountains of Kwangtung and Fokien provinces and some 

 in the more distant Yunnan province. The island of Hainan remains 

 little known and though the flora is doubtless rich in endemic plants it 

 is related to that of Mindanao Island on the one hand and continental 

 China and Tonking on the other. 



So far as Rhododendrons are concerned the species found in the 

 different regions are mostly local in distribution. From the whole ter- 

 ritory under survey some 40 species are at present known but our knowl- 

 edge of the flora of Fokien and southeastern China is exceedingly limited 

 and without doubt many new Rhododendrons remain to be discovered. 

 Nevertheless the whole region represents merely the fringe of distri- 

 bution and is in no sense a centre of the Rhododendron family. Still 

 it is worthy of investigation and many of its Rhododendrons are hand- 

 some plants. 



From Bonin, Liukiu and Formosa some 22 species of Rhododendron 

 are at present known, of wdiich 18 are endemic. The first known was 

 R. scabrum, named by G. Don in 1834, native of the Liukiu and long 

 cultivated in south Japan, but how and where Don obtained his material 

 we do not know. The last discovered was R. boninense Nakai in 1920 

 and introduced into cultivation by means of seeds which I secured through 

 Dr. Nakai's assistance in the late autumn of 1924. The first Formosan 

 species discovered was R. Oldhamii by Richard Oldham in 1864 after 

 whom it was named by the Russian botanist Maximowicz. It was 

 introduced into cultivation in 1878 by Charles Maries and reintroduced 

 by myself in 1918 at which time I also introduced three other species 

 from Formosa. The remaining endemic species are not yet in cultivation 

 though several are well worthy of the honor. 



The Bonin species {R. boninense Nakai) is known from one isolated 

 locality only and is the most eastern and remote representative of the 

 Azalea group. With its white flowers it reminds one of R. mucronatum 

 G. Don, better known as Azalea ledifolia. 



From the Liukiu Archipelago and the neighboring Kawanabe Islands, 

 four species of Rhododendron are known. One species, the red-flowered 

 R. scabrum G. Don, better known as Azalea sublanceolata, is endemic, so, 

 too, is the variety eriocarpum Ilayata of R. Si?usii Planch, known only 

 from the Kawanabe Islands. R. Tashiroi Maxim, is common on Yaku- 

 shima and grows also on Mt. Kirishima and elsewhere in Kyushu, Japan. 

 The fourth species, R. leiopodnm Ilayata, is common to Yaeyama, the 



