204 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



in the Rhododendrons ; most of the finer species of the genus dis- 

 covered by Delavay are indigenous to the range ; in the gullies 

 and gorges one comes on them at every turn, either as solitary speci- 

 mens or in groups, sheltered and supported by a jungle of mixed 

 scrub and cane. In shady places, such species as R. neriifiorum 

 and R. huematodes eclipse everything in beauty with their cherry- 

 coloured and deep crimson blooms, whilst again, beneath their shade, 

 is found the dwarf est of all known species from the region, R. campy- 

 logynum, only a few inches in height, with pendulous, dark plum- 

 purple, bell-like corollas. R. brochyanthum is another dwarf with 

 dull greenish- yellow flowers of similar shape and substance. R. 

 bullatum is also partial to shade, and is found in company with the 

 above, but is never so abundant though more widely distributed. It 

 is a real rock shrub, and its large fragrant white blooms are most 

 ornamental (fig. 68). 



Other species, growing more in the open, are R. ciliicalyx, with 

 flowers white, flushed rose on exterior, and R. crassum, both as rock 

 plants. R. racemosum, R. oleiifolium, R. microphyton, R. trichocladum, 

 R. rigidum, and R. aureum are, more or less, grassland plants, and are 

 found in open and drier situations. 



At higher altitudes, forming open thickets and even forests, are 

 found the taller species, as R. Delavayi, R. irroratum, R. decorum, R. 

 taliense, R. yunnanense, R. rubiginosum, and R. cyanocarpum, whilst 

 highest of all, carrying the genus up to the extreme alps, is R. sul- 

 fur eum, and many delightful forms and species of the R. fasti giatum 

 and R. intricatum groups. Since the days of Pere Delavay's collecting 

 many excellent new species have been added to the list, as R. dichro- 

 anihum Diels, with large, deep red-orange blooms ; another species, 

 as yet unnamed, with large compact trusses of canary-yellow flowers, 

 a tree species after the style of R. Wightii ; R. Beesianum, R. 

 Balfourianum, R. prostratum, &c. 



Recently there has been much discussion regarding lime and 

 Ericaceous plants, especially as applied to the cultivation of Rhodo- 

 dendrons. As already mentioned, most, if not all, of the mountain 

 ranges of W. and N.-W. Yunnan are solely limestone formations, and 

 it is on those the greater number of the Rhododendrons are found. 

 I am not in a position to give a decided opinion, but this I can state 

 positively, that most of the Rhododendrons I have collected in that 

 region grow directly in, or on, pure limestone. Many of the smaller 

 shrubs, such as R. neriifiorum, R. floccigerum, R. sanguineum, R. 

 bullatum, R. ciliicalyx, R. crassum, R. yunnanense, R. aureum, &c, 

 and the dwarf species R. campylogynum, R. brachyanthum, R. tricho- 

 cladum, and forms of R. intricatum, have their roots embedded in 

 the crevices of the limestone rocks or cliffs, or in the limy rubble at 

 their base ; whilst the taller tree species, though with more or 

 less of a bed of humus for support, have their smaller roots similarly 

 placed. 



Even the lower-level species, such as R. rigidum, and forms of 



