Mai'(~h, 
III 
ORCHID WORLD. 
DENDROBIUM THYRSI FLORUM. 
DENDROBIITM thyrsiflorum owes its 
specific name to the mail)' th\ i'ses, or 
dense panicles of flowers, which are 
produced during the spring-time. By some 
botanists this Burmese plant has been 
regarded as a variety of D. densiflorum, from 
which it differs m several 
important points. Reichen- 
bach, however, separated it as 
a distinct species, and as such 
it is generally considered. In 
both plants the unexpanded 
racemes ha\'e a curious cone- 
like appearance, probably 
unique in the genus. This is 
caused by the flower buds 
being completel)' enveloped 
m and concealed by the large 
imbricate yellow floral bracts. 
D. densiflorum has dis- 
tinctly four-angled bulbs, 
whereas D. thyrsiflorum has 
more slender stems, and the 
floral bracts are much nar- 
rower than in typical plants 
of the former species. Many 
growers can easily discern 
the difference between the 
two species, and when im- 
]iortations of both plants 
arrive in a mixed state, they 
have no difficulty in separ- 
ating them. The two species 
appear to grow in different 
localities, and there does not 
appear to be any evidence 
that they grow together. D. 
densiflorum invariably has 
pale yellow sepals and petals, 
the lip being of a rich orange- 
yellow, often paler towards the margins. 
D. thyrsiflorum has white flowers with a 
golden-yellow lip, although a few varieties 
are occasional!)- seen with a pale lilac 
suffusion m the sepals. A variety knovvii as 
Walkerianum had stems three feet m height, 
and the racemes of flowers were two feet long, 
bearing more than fifty flowers on one 
raceme. This may have been an exceptionally 
strong and recently imported plant, and there 
is no record that such a \igorous state 
was maintained. Our illustration shows 
D. th)'rsiflorum flowering m the collection ol 
E. H. Andriesse, I'Lsq., Dampit, Ja\a. 
Dendrobium thyrsiflorum, in the collection of E. H. Andriesse, Esq., 
Dampit, Java. 
D. Farmeri has prominently angled bulbs 
of 12 to 1 8 inches in height, and is in many 
ways similar to the above species. The 
raceme is more loosely flowered, the sepals 
and petals when first expanding are often of 
a pale mauve colour, which changes in the 
course of a few days to pure white. The lip 
13 of a deep rich yellow, the margin often pure 
