Note on Lo-Kao. 
it is R. utilis^ Dene, and therefore true R. davuricus, Pall. It is 
exceedingly like specimens of veritable R. davuricus here. Dr. 
King tells me the plant is grown in Java only as a curiosity. 
The history of the plant sent from China by Fortune is short. 
The account of it in Vol. ix. i° ser. of the Society’s Journal shews 
that under the special treatment it received in their garden it did 
fairly well. When the old site was abandoned, the ground re¬ 
verted to the Botanical Garden, and as the plant appears to have 
attracted no attention on the part of the public, the special treat¬ 
ment does not seem to have been continued. Left to itself it 
shewed its exotic nature and within a few seasons all the speci¬ 
mens died. It would be interesting to ascertain if any of the 
older members of the Society have continued the cultivation of 
the plant and still preserve it. But its not being generally grown 
seems to point to practical difficulties, and this is borne out by 
its speedy extinction when left to itself. 
The geographical limits of the species are as follows : — 
R. davuricus ; N. China, Mandshuria, E. Siberia. 
R. tinctorius ; Mid and N. China, Asia Minor, S. E. Europe. 
R, sp.; Central S. China, but at 6,500 elevation there. 
It is therefore doubtful whether perfect naturalization of these 
in the plains of India can be hop d for. Moreover, all the in¬ 
digenous species are high level plants, the lowest elevation quoted 
(for one species only, R. persicus, Boiss), being 2,000, the usual 
range being 5,000 to 9,000. But it is likely that the Chinese 
species would thrive well at similar levels. It would be interest¬ 
ing to ascertain whether any of the indigenous species, one at 
least of which has been referred to a dye-yielding species, would 
not, if suitably treated, yield a similar dye. The property, as has 
been shewn, is shared by at least three Chinese species. 
Mr. Blechynden suggests the recapitulation of the Chinese 
method of preparing the dye. This is to be found in the Society’s 
Journal^ loc. cit., 276, and it is to be noted that in Fortune’s 
account of the process, and also in McMurray’s account of the 
cultivation of the plant which accompanies it, two varieties^ a wild 
and a cultivated, are spoken of, the presence of both being 
necessary for the production of the dye. These varieties are 
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