158 JOURNAL OF THE ARNOLD ARBORETUM [vol. vi 



most southern of the Liukiu Islands, and to Formosa. On Okinawa, 

 R. scabrum G. Don with large gorgeous red flowers is, locally, fairly 

 plentiful hut nowhere in the Liukiu Archipelago are Rhododendrons 

 a prominent feature of the vegetation, neither can they be called common 



plants. 



Three common east China Rhododendrons (R. Simsii Planch., R. 

 Mariesii llemsl. & Wils., R. ovatum Planch.) have just a foothold on 

 Formosa, but all are rare plants there. This island with its high moun- 

 tains and magnificent forests has so far yielded 19 species of Rhododen- 

 dron of which 15 are endemic. On the higher mountains R. Morii Hayata 

 and R. pseudochrysanthum Hayata are abundant as undergrowth in 



the forests of Fir, Spruce and Juniper, growing socially and covering 

 large areas. R. psevdo-chrysanthum Hayata extends well above the 

 tree line and as a low shrub with gnarled branches grows on the summit 

 of Mt. Morrison, 13,072 ft. above sea-level. On rocky ridges and slopes 

 between 11,000 and 13,000 ft. it forms with Juniperus morrisonicola 

 Hayata well-nigb impenetrable thickets. Rut it is only on the higher 

 parts of this central range that one familiar with Rhododendrons in 

 western China and Japan would call them common plants in Formosa. 

 In the rich rain-forests on Arisan between 6000 and 8500 ft. altitude 

 the epiphytic R. Kawakamii Hayata is moderately plentiful. On open 

 grass-clad deforested mountain slopes beyond Arisan and toward Mt. 

 Morrison one Azalea (R. rubropilosum Hayata) grows socially in con- 

 siderable numbers. Through forests of mixed trees R. leiopodum Hayata 



is 



From sea-level up to 7500 ft. altitude, the red-flowered R. Oldhamii 



Maxim, is plentiful being the low-level Azalea of the islands and in this 

 respect the homologue of R. Simsii Planch, in China and R. obtusum 

 Planch, in Japan. The other Formosa species may be considered rare 

 in the present state of our knowledge. 



In all 21 species of Rhododendron are known from the mainland of 

 eastern China, 14 of which have not been reported from elsewhere. 

 Of this region I have but little personal acquaintance. On the Lushan 

 Mountains in Kiangsi I have collected R. Fortunei Lindl., R. ovatum 

 Planch., R. Mariesii llemsl. & Wils., R. molle G. Don and R. Simsii 

 Planch., and on Hongkong have seen R. Cham pinnae Hook, in a wild 

 state. On the Lushan only /v. Simsii Planch, and /?. oratum Planch. 

 are common plants. The first-named is found everywhere in China 

 from sea-level up to (5000 feet except in the north where the climate is 

 too severe. Rhododendron Fortunei Lindl. was the first true Rhododen- 

 dron introduced from the Orient. This handsome species with its frag- 

 rant, pink, 7-lobed flowers has been of immense service to Rhododendron 

 breeders, in England especially, and is part parent of a race of magnificent 

 hybrids now widely cultivated. R. ovatum Planch., like R. Mariesii 

 Hemsl. and R. molle G. Don, has its western limits in Hupeli province. 



attercd over much of the island between 2000 and 8000 ft. altitude. 



