ACCOUNT OF GENUS SEDUM AS FOUND IN CULTIVATION. 27 



Group I. RosEAE. — Caudex-leaves scale-like, short, membranous, 

 seldom green even when young. Old flower-stems not persistent. 

 (P. 28.) 



roseum Scop. elongatum Wall. 



heterodontum H. f. and T. bhutanense Praeger. 



Kifilowii Kegel. purpureoviride Praeger. 



longicaule Praeger. bupleuroides Wall. 



rotundatum Hemsl. 

 Group 2. HiMALENSES.— Caudex-leaves scale-like, usually green 

 and fleshy when young, often prolonged into a short narrow blade 

 or tail. Old flower-stems usually persistent. (P. 49.) 



iibeticum H. f. and T. himalense Don. 



quadrifidum Pallas. fastigiatum H. f. and T. 



Series 11. Crassipedes. 



Flowers hermaphrodite and 5-parted. Caudex as in the Rhodiolae 

 s.s. Caudex-leaves as in the Himalenses. Flower-stems persistent 

 or deciduous. Carpels usually slender, with slender styles not reflexed 

 in fruit. (P. 55.) 



crassipes Wall. trifidum Wall. 



Stephani Cham. Semenovii Masters. 



dumulosum Franch. rhodanthum A. Gray. 



Series III. Primuloides. 



Flowers as in the Crassipedes. Caudex slender elongate, or 

 short not much thickened (comparatively). Caudex-leaves leaf- 

 like, with a distinct blade, usually stalked. 



Group I. Longicaules. — Rootstock elongate, much branched. 



primuloides Franchet. 

 Group 2. Brevicaules.— Rootstock very short, branched shghtly 

 or not at all. 



Praegerianum W. W. Sm. 



Rhodiola is essentially an Asiatic and sub-alpine group, finding 

 its maximum development in the great mountain area stretching 

 from Afghanistan to Yunnan. Northward it extends into the Arctic 

 Regions; southward its range is Iknited. One species, S. roseum, 

 which is also the most variable of the group, is circumpolar in its 

 distribution. Another, 5. rhodanthum, is confined to North America. 

 Of the group in its wide sense, as used in this paper, about fifty 

 species have been described, of which twenty-one are in cultivation, as 

 listed above and described below. 



The great variabihty of many of the species (see Hooker and 

 Thomson in Journ. Linn. Soc. Bot., vol. ii. p. 93) renders diagnosis 

 often difficult. Especially as regards the colour of the different 



