1916-17. 1 BOTANICAL SOCIETY OF EDINBURGH 167 



not found 14 stamens. The stamens are always unequal in 

 length, the longest usually about a centimeter longer than 

 the shortest, but in Rh. gyninanthuin and R]i. spanotrichum 

 the difference is quite 2 cm. The longest stamens in the 

 series are those of the larger flowers in Rh. irroratum. 

 They may be 4'5 cm. long, whilst in the shorter flowers of 

 that species they are only 3 cm. Rlt. araiophylluni, which 

 has the smallest flowers of all the species, has stamens show- 

 ing smallest dimensions — the longest only 2'8 cm. long. In 

 four of the species the filaments are glabrous {Rh. eritimum, 

 Rh. lukiangense, Rh. spanotrichuin, Rh. tanastylum). 

 Diels assigns glabrous filaments to Rh. gyTYinanthum, but 

 hairs are present, few perhaps, and only developed a short 

 distance above the base of the filaments — in other species 

 which have hair-appendages to the filaments they start 

 from the very base ; there is no naked base to the filaments 

 as in some other series of Rhododrendron. The hairiness of 

 the filaments in these other species may amount to puber- 

 ulousness only, often in very fine degree {Rh. antho- 

 sphaerwrn, Rh. ceraceitm, Rh. irroratum, Rh. ojiengtszense), 

 or may be a true pubescence {Rh. adenostemonum, Rh. 

 agastum, Rh. araiophyllum, Rh. hylothreptum), and it is 

 usually confined to the base of the filament up to about 

 the top of the ovary. In Rh. adenosteinonutn, Rh. hylo- 

 threptum, and Rlt. pogonostylum it extends much further 

 up the filament to its middle or beyond that, and in Rh. 

 adenosteinonuin we have this unique feature, that mixed 

 with the hairs and above the limit to which they reach 

 are red, shortly-stalked glands — an unusual occurrence. 



The character of the disk is not sufiicientl}^ taken note 

 of in Rhododendrons. Measurements of the ovary include 

 sometimes I think the disk, and where it is very hairy the 

 character may easily be assigned to the ovary. In the 

 Irroratum series the disk is short and smooth, quite 

 glabrous {Rh. anthosphaerum, Rh. araiophyllum, Rh. 

 eritimuin, Rh. gymnanthum, Rh. irroratum, Rh. pogono- 

 stylum, Rh. spanotrichum, Rh. tanastylum) ; hairy in 

 degrees of pubescence and puberulousness {Rh. adeno- 

 stemonum, Rh. ceraceum, Rlt. hylothreptum (minutely), 

 Rh. lukiangense, Rh. mengtszense) ; floccose (Rh. agastum). 



The gynaeceum is a little longer than the stamens and 



