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LAPPONICUM SERIES OF RHODODENDRONS. 
Contributed by Professor Bayley Balfour, F.R.S. 
I wonder if I might ask for the hospitality of the Rhododendron Society in 
the matter of obtaining information about the yellow-flowered forms of the 
Lapponicum Series of Rhododendrons that are in cultivation ? I may best 
make clear what I want by a tabular statement;— 
1. Veitch raised from Wilson’s seed No. 1778, sent home in 1904, the plant 
named by Hemsley, R. primulinum (see Card. Chron.3, XLVII. (1910), 4 and 
229, fig. 101). 
2. Before this name had been long in circulation, Hemsley and Wilson, 
in the Kew Bulletin (1910, p. 117), sank Hemsley’s name R. primulinum in 
R. FLAVIDUM, Franchet. This original Wilsonian plant is therefore met with in 
cultivation under both names. 
3. Wilson, in his first Arnold Arboretum Expedition in 1908, obtained seeds 
of what he considered the same plant, and it was distributed under No. 1202. Is 
this plant in general cultivation ? 
4. We have a plant of this No. 1202 raised from Wilson’s seed. It has not 
yet flowered. It is named R. flavidum on the authority of the Plants 
Wilsonian.® but it is a very different plant from Wilson’s 1778. An obvious 
structural difference is visible on the under side of the leaf. The scales of W. 1778 
are of one colour and all far apart, in W. 1202 the scales are of two colours and are 
close together. 
6. What I want to request is that those who grow plants under Wilson’s 
Nos. 1778 and 1202, or under the names R. flavidum and R. primulinum, 
would examine them and see whether all the plants they have are the same in 
character of foliage. If the plant has flower or should flower a difference to be 
looked for is this :—.Wilson’s No. 1778 should have a corolla hairy and coated 
with scales on the outside and it should also h^ve a style more or less hairy. I 
have ground for thinking that the flowers of No. 1202 will not show any hairs on 
the outside of the corolla and may have a hairless style. 
ISAAC BAYLEY BALFOUR. 
Royal Botanic Garden, Edinburgh, 
27iA January, 1917. 
151 
