P late X V III.
DENDROBIUM COERULESCENS.
D. coerulescens; caule erecto carnoso tereti, foliis oblongis obtusis emarginatis subun-
dulatis, racemis horizontalibus 2-3-floris foliis paulô brevioribus, perianthio
explanato, sepalis lineari-oblongis obtusis emarginatis lateralibus basi paulô
productis, petalis latioribus oblongis apice recurvis, labello ovali subundulato
utrinque pubescente apice constricto piano glabro recurvo, antherâ pubescente.
D. coerulescens, JVallich Mss.
The species now represented has altogether the habit of Dendrobium nobile; when out of
flower it so much resembles that species that it may be supposed to be the same. In this respect
it accords with several others of the genus, such as the Dendrobia Pierardi, cucullatum, and
macrostachyum, which can scarcely be distinguished by their foliage. When in flower it is
strikingly different from Dendrobium nobile; perhaps it is not quite so handsome, for it wants the
very rich purple- of that species ; but in other respects it has beautiful features of its own.
The sepals and petals have a delicate tinge of very pale bluish lilac, especially on their back, and
their form is more slender and graceful. Specific differences between the two are furnished by the
shape of the lip and sepals, both of which are much narrower than in Dendrobium nobile, and the
former has quite a. different outline, as will be obvious upon comparison of the accompanying
figure, and that at plate 3 of this work.
It was collected for His Grace the Duke of Devonshire, by Mr. John Gibson, at Nungklow, on
the northern face of the Khoseea range of hills, where it grows upon rocks and trunks of trees, at an
elevation of not less than 4000 feet. The specimen now figured is sufficiently beautiful with only
ten flowers upon it; but Mr. Gibson states that he found it loaded with from thirty to forty flowers
on a stem. The accompanying plate has been prepared from a drawing and specimens sent by
Mr. Paxton from Chatsworth, where it blossomed in April 1838.
The s e p a l s , which spread nearly at equal angles from each other, are about an inch and half
long, and a quarter of an inch wide; they are of a delicate bluish lilac colour, tinged with
deeper purple at their ends, and slightly pitted all over between the veins so as to acquire a
somewhat tessellated appearance ; they are all notched at the apex, and the; lateral ones are slightly
extended on one side into a short blunt spur. The p e t a l s are coloured like the sepals, except that
they are rather darker, and less tessellated ; they are oval, not emarginate, but undulated and
curved back at their end. The l i p is very exactly oval and concave, except that it is extended
into a narrow flat obtuse point, which is curved downwards; its sides are rolled round the column
at the base, and then curved outwards and undulated ; it is rich crimson in the middle, yellow at
the edge, deep rose colour at the apex, and is covered with conspicuous pubescence every where
except at the point; as the flowers fade, the yellow changes to brownish purple, and becomes marked
with purple veins. The c o l u m n is very short, flat, and sloped forwards in front, convex at the
back ; it is terminated by a peaked, purple, hairy anther.
Fig. 1. represents the column and anther, with the bases of the sepals and petals, the lip being
removed. Fig. 2. is the lip unrolled, rather magnified, and seen from above.