THE BOTANY OF CHRISTMAS ISLAND. 233 



Dendrobiwns of the section Desmotrichum are very difficult 

 to describe from dried specimens, as the flowers are of 

 thin texture and very fugacious, and as they only open 

 for a few hours in the morning and are withered by 

 midday. It is not often that collectors can procure 

 good specimens. These are- no doubt the reason why 

 there has been so much confusion over these plants and 

 for the identification of the Christmas Island plant with 

 D. Macraei Lidley a species apparently confined to 

 Ceylon, and utterly different, belonging indeed to a 

 different, subsection. 



In the Flora of British India, a number of different 

 species are recorded as synonymous with D. Macraei, 

 including the Himalayan D. Rabani and Javanese 

 D. flabellu?n, a plant with large red spotted flowers. D. 

 pectinatum is more nearly allied to the D. calopogon Rihb. 

 fil, Xenia, Orch. p. 23 pi. 109, fig. 1. 2. of unknown locality 

 but differs in the form of pseudobulb and narrow claw of 

 the lip, and I cannot identify it with any described 

 species. A considerable number of Javanese Desmotri- 

 chums were described by Blume in the Bijdragen, but as 

 in most of his early work so badly that it is utterly 

 impossible to guess at what he meant, and thus they had 

 better be relegated to the class of tiomina nuda and 

 ignored. 



D. crumenatum, Sw. 



Common all over the island especially on trees on the 

 Plateau. The plant which is quite typical, was scantily 

 in flower at the time of our visit. I obtained it in 

 1890 and Andrews also got it. 



Distribution, Malay Peninsula and Islands, Southern 

 Siam. 



Phreatia Listeri, Rolf e. 



A small orchid with greenish white flowers in slender 

 spikes. Common on trees on the Plateau. 



Endemic. Collected also by Lister and Andrews. 



B. A. Soc, Xo. 45, 1905. 



