148 BALFOUR—NEW SPECIES OF RHODODENDRON, 
the bottom of a groove. In Rh. sciaphilum there is sometimes, 
particularly towards the margin and top of the leaf, a suggestion 
of this, but generally the surface is smooth and the primary 
veins have no groove above them. And then Rh. sciaphilum 
is wanting, as Mr. Kingdon Ward tells us, in the character 
which is so strongly developed in the allied species—fragrance 
of the flower. 
The discovery of Rh. sciaphilum in the Naung Chaung Valley 
in E. Upper Burma establishes an interesting geographical link 
between the Himalayan and the West Chinese flora. The 
series to which it belongs we may speak of as the Edgeworthii 
series, after the well-known Himalayan Rh. Edgeworthi, the first 
described of the species now placed in it. 
The description by Franchet in 1887 of Delavay’s specimens 
of Rh. bullatum and Rh. Bureavi put on record that the type of 
Rh. Edgeworthii, before then known only from Sikkim and Bhutan 
through the explorations in the middle of last century of Sir 
Joseph Hooker, of Griffith, and of Booth, had a spread far east- 
wards in the western region of Yunnan. Then the distribution 
was carried farther eastwards by the discovery by Maire of 
Rh. cruentum in N.E. Yunnan, and now Ward’s plant RA. 
sciaphilum comes to show us that the type is to be found in the 
region between the Himalayas on the west and Yunnan on the 
east, and suggests that there may be other forms of it yet to be 
discovered over this broad unexplored area. In the following 
list I give the names of the five known species of the Edge- 
worthii series, the general distribution of each species, and the 
name of its discoverer :-— 
Rh. bullatum, Franch. (1887). Mid. W. Yunnan: Tali, 8000 
ft. (Delavay, 1889.) 
W.N. unnan: Tseku. 
(Soulié, 1903.) 
E.N.W. Yunnan: Chungtien 
Plateau, 12,000-13,000 ft. 
(Forrest, 1904.) 
. Yunnan: Tengyueh and 
Shweli - Salween divide, 
8000-10,000 ft. (Forrest, 
Rh. Bureavi, Franch. (1887). Mid. W. rane Langkiun 
10,000 ft. (Delavay, 7886) 
E.N.W. Yunnan: Sungkwei 
and in N.E. of Yangtze 
bend, 10,000-12,000 ft. 
(Forrest, 1904.) 
