VANDA. 



95 



conical ; callus two-lobed, on eacli side of which is a semi-lunate 



orange-yellow blotch. 



Vanda Denisoniana, Benson and Rchb. in Gard. Chron. 1869, p. 528. Bot. Mag. 

 t. 5811. lllus. liort. 1872, t. 105. Hook, f, Fl. Brit. Ind. VI. p. 51. 



var.— hebraica. * 



" Sepals and petals sulphur-yellow marked with numerous spots, 



transverse short bars and figures comparable with the Greek letter A ; 



lip sulphur-yellow, the lateral lobes paler ; spur orange inside." 



V. Denisoniana hebraica, Rchb. in Gard. Chron. XXIV. (1885), p. 39. Williams' 

 Orch. Alb. VI. t. 248. 



Vauda Denisoniana. 



Discovered by Colonel (now General) Benson growing in sheltered 

 and shaded spots on large trees on the Arracan Mountains westward 

 from Prome, at an altitude of 2,000 — 2,500 feet, where the mean 

 temperature is about 21° C, (70° F.), and the average yearly rainfall 

 is from 90—100 inches.t It was introduced by us through Colonel 

 Benson in 1868, and it flowered for the first time in this country 



* Not seen by us. 



t Colonel Benson in Gard. Chron. 1870, p. 796, who gives the following further particulars of 

 the climate of that part of Lower Burmah: — "These mountains (Arracan) form as it were a 

 barrier to the south-west monsoon, arresting its force to the eastward, consequently the country 

 around Prome and Thayetmyo has a considerably drier climate than that about Eancmon and 

 Moulmein. Thus the rainfall on the Prome or east side is very much less than on^the west 

 side, which is exposed to the full volume of the south-west monsoon coming direct from the 

 ocean. Although the rainfall on the east side is gi'eatly diminished in intensity, yet rain 

 clouds hang about the tops of these hills, giving them a watery vapour, an atmosphere in which 

 these plants (orchids) delight, but without a great deluge of rain," 



