206 TRANSACTIONS OF THE [Sess. lxxxi 



glabrous not iioccose pedicels, its glabrous not puberulous 

 stamens, its pubescent not glabrous disk. 



I will not quarrel with Franchet's ascription ot" Rh. 

 lukiangense to the Arboreum group of Rhododendrons em- 

 bracing "species with 5-lobed corolla and 10 stamens" — only 

 the great increase in the number of known Rhododendrons 

 since he wrote compels endeavour to find smaller phyletic 

 groups within the genus, and the -Irroratum series is a 

 product. The Arboreum series of Rhododendron centering 

 in the Himalayan Rh. arboreum, with its allied forms 

 RJi. Camphdliae, RJi. cinnamomeum, Rh. Kingianum, 

 Rh. nilagiricum, Rlt. Rollissonii, and so forth, is repre- 

 sented in China by Rh. Delavayi, which also seems to have 

 some distinct enough allied forms, and the series can be 

 readily separated b}^ valid marks as a phylum from the 

 Irroratum series. It is true that the general habit of some 

 members of the Irroratum series recalls the Arboreum habit, 

 and there is also often the compact truss of red flowers, but 

 the indumentum of the Arboreums has a XQvy different con- 

 struction from that of the Irroratums. This and the many 

 other distinctions between the series I must leave over for 

 another occasion of a\ riting. Only one thing further will 

 I say here, that no one of the Chinese Irroratums can 

 compare in consistency of corolla and intensity of colour 

 with Rh. arhorciiin. And this is not an isolated case in 

 a comparison of the Rhododendrons of the two areas. As 

 a whole the large Sikkim Rhododendrons bear the palm 

 in these respects ever the Chinese — only in some of the 

 dwarfer Chinese forms is there rivalry. 



Fi-anchet also mentions RIl. Bonvaloti, Franch. as a species 

 whicli RJi. luhlungense "specially resembles." I have know- 

 ledge of Rh. Bonvaloti only in a fragmentary specimen, and 

 it would lead me to exclude it from the Irroratum series, but 

 I shall have to deal with Rh. Bonvaloti at another time. 



Rliododendron rnengtszense, Balf. f. et W. W. Sm.^ 



Tree reaching a height of about 6 m. with slender 

 branches covered with the agglutinated remains of seti- 



1 lihododendrun memjtszense, Balf. f. et W. W. Sm. — Arbor ad 6 m. alta 

 temiiramosa glandularuni setiforniium et cataphyllornm et bractearum 

 annorum praeteritoruin vestigiis agglutinatis obtecta. Rami ■ apiceni 



