" 
JuNE, 1918.] THE ORCHID REVIEW. 131 
st 
HIS interesting Masdevallia has recently flowered freely at Kew, and has 
afforded an opportunity of observing the sensitive character of the lip, 
which was originally discovered over thirty years ago. When the flower 
first opens, the tails of the sepals turn back and the lip is seen folded up 
just beneath the arch of the petals. Presently the triangular blade falls 
down between the lateral sepals, disclosing a yellow ridge on the disc, 
which is the seat of irritability. On touching this gently with a hair, the 
lip is at once raised, at first slowly and then closes suddenly, with a snap. 
In about twenty minutes it descends again, and on being again touched it 
closes just as quickly as before. Mr. Bean, who originally made the 
discovery, placed awinged aphis on the lip, which was carried up and held 
firmly, and the same happened when a house-fly was tried. This is 
evidently the mechanism by which the flowers are fertilized in a wild state. 
An insect alighting on the lip would certainly touch the ridge, and would be 
lifted up and imprisoned in the ‘ box’ formed when the lip is closed. The 
excessive hairiness of the scapes and ovaries no doubt serves to prevent 
crawling insects from reaching the flowers. A figure of the plant may be 
seen at t. 7664 of the Botanical Magazine, and it may be added that the lip 
of M. xipheres, Rchb. f., also at Kew, behaves in precisely the same way. 
MASDEVALLIA MUSCOSA. Hel 
ORCHIS PURPUREA ALBIDA.—Orchis purpurea, often known under its 
later name of O. fusca, is a handsome species of Orchis that is found locally 
in Kent, sometimes, we believe, in abundance, and Mr. F. J. Hanbury, in 
his Flora of Kent (p. 330) mentions that it occurs rarely with white flowers. 
A very light-coloured form has been sent to Kew, with the following note. 
“It was found growing in one place only, side by side with O. fusca. I 
have observed these two for several years, and no intermediate forms occur. 
Friends who have observed these flowers for a long time tell me that the 
pink one is known as large as four feet high, in any case it isa much more 
robust plant than the type, which is also sent. Another peculiarity of this 
is that very frequently a large number of its flowers have untwisted ovaries, 
as in the specimen sent.—G. L. Davidson, R.E. Mess, Aldershot.” It is 
near the variety known on the Continent as O. purpurea albida, in which 
the lip is said to be entirely white, though we believe the colour is retained 
in the sepals and petals. In this case the whole flowers are very pale, with 
obscure markings, and the vigorous habit and untwisted ovary are as 
described —R.A.R, 7 
