SHRUBBY AND SUB-SHRUBBY FLOWERS. 129 



coloured, bell-shaped flowers grow together in bunches 

 of six or eight, and glow with the most vivid crimson. 

 All the Rhododendrons are American plants, in the gar- 

 dening sense ; they have fibrous roots, which are seriously 

 injured or killed by drought, and they must have some 

 sort, or imitation, of heath-mould. Where this is not to 

 be had from a natural source, within a convenient dis- 

 tance, a substitute may be manufactured by thoroughly 

 combining silver-sand with leaf-mould, rotten sawdust, 

 rotten tan, little bits of stick, and the refuse of a wood- 

 stack charred in an oven to kill the insects, light loam, 

 and vegetable refuse in which the seeds and creeping 

 roots of weeds have been deprived of their troublesome 

 vitality. Rhododendrons must have a certain amount of 

 shade ; and therefore, when not under lofty trees (which 

 is their natural position), they do best with a north or 

 north-east exposure. It is curious that several of the 

 Sikkim species, — for instance, pendulum and Dallwusice, 

 are epiphytes ; that is, they grow on the branches of 

 trees, where their roots find support and nourishment 

 by penetrating the moss and loose bark. Nevertheless, 

 they grow well in pots, and in the open ground, in 

 heath-mould, with good drainage at bottom, and a moist 

 atmosphere above. As the hardiness of these novelties 

 is scarcely yet ascertained with accuracy, it will be safer 

 to house valuable specimens in a greenhouse in winter ; 

 still there is every reason to hope that they will be found 

 to adapt themselves to the British climate, if proper 

 attention be paid to their peculiar requirements of shade, 

 a peaty soil, and a constant infiltration of moisture. At 

 least they are well worth the risk of experiment. Thus, 

 JR. glaucum, light purple, grows in the clefts of rocks at 

 an altitude of four thousand feet ; B. lanatum has large 

 leaves and light-yellow flowers with a bright orange spot 

 and purple speckles, within ; B. triflorum has pale- 

 yellow flowers, growing by threes at the tips of the 

 young shoots ; B. Maddeni has large white blossoms 

 delicately washed with pink outside ; B. argenteum is so 

 named because its leaves, dark green above, are silver- 



