February, 1915.] 'IHR ORCHID WORLD. 103 



STANHOPEAS. 



THE genus Stanhopea was proposed by 

 Mr. John Frost, of Kew, for S. 

 insignis, which flowered in the Royal 

 Gardens in October, 1829, and was communi- 

 cated by him to Dr. (afterwards Sir Wilham) 

 Hooker, by whom it was described in the 

 Botanical Magazine, t. 2948. It was named 

 in compHment to Earl Stanhope, at that time 

 President of the Medico-Botanical Society in 

 London. 



The flowers are very large, with 

 membraneous sepals and petals of compara- 

 tively simple form, while the labellum is 

 fleshy and of complex structure, the most 

 obvious parts of which will be easily 

 recognised from the accompanying illustra- 

 tion ; for so curious are the different parts of 

 the lip of a Stanhopea, that a clear description 

 of them without such assistance is well-nigh 

 impossible. 



The three parts of the labellum are thus 

 distinguished : (i) Hypochile, the basal 

 portion which is affixed to the base of the 

 column ; this is always saccate or hollowed 

 out from above, sometimes globose in outline, 

 sometimes elongated into the form of a boat. 

 (2) Mesochile, the middle portion consisting 

 of two horn-like bodies either bent round and 

 parallel with the sides of the epichile or bent 

 upwards at a considerable angle to it. (3) 

 Epichile, the apical portion, which is 

 polymorphous, being cordate, ovate, sub- 



rhomboidal or even oblong. Both mesochile 

 and epichile are of wax-like appearance, 

 usually white or colourless, but sometimes 

 spotted. The column is greatly elongated, 

 arching over the labellum, almost meeting it 

 at its apex ; the wings are membraneous and 

 dilated beyond the middle. 



It is certain, state Messrs. Veitch and Sons, 

 that the remarkable structure described above 

 is all important in the economy of the plant 

 and its perpetuation, but why so complex a 

 mechanism has become necessary to its 

 existence and the modifications it has 

 undergone in the lapse of ages before 

 attaining its present form are still among the 

 secrets of Nature. The powerful odour 

 exhaled by the flowers of most of the species, 

 and which are all of short duration, is 

 doubtless an incentive to the larger insects to 

 visit the flowers and to make their way into 

 the hypochile where honey would be likely 

 to be secreted or with the object of gnawing 

 the interior lining which they are said to 

 devour with great avidity, and the forms of 

 the mesochile and epichile are among the 

 contrivances to induce the insect to leave the 

 flower through the opening between the apex 

 of the latter and that of the column, in which 

 case the pollinia would be removed while 

 pressing its way through. For effective 

 fertilisation, this hypothesis demands the 

 alighting of an insect already loaded with 

 pollinia on another unfertilised flower, and 

 when passing through the apical opening the 

 pollinia would be deposited on the stigma. 



