808 MR. H. N. RIDLEY’S REVISION OF THE 
A Revision of the Genera Microstylis and Malazis. 
By H. N. Rivtey, M.A., F.L.S. 
[Read 16th June, 1887.] 
Tux genera treated of in this paper, together with Oberonia and 
Liparis, constitute a fairly natural group of Orchids, the Ma- 
laxidee. Mr. Bentham, in ‘Genera Plantarum,’ iii. p. 465, 
separates the group into Malaxee, comprising Malavis and Mi- 
crostylis, and Lipariee, including Oberonia, Liparis, Platyclinis, 
Calypso, Oreorchis, Corallorhiza, Tipularia, Aplectrum, and Heza- 
lectris. Dr. Pfitzer, in his recently published * Entwurf einer 
naturlichen Anordnung der Orchideen,’ expels from the section 
the last three genera and Platyclinis, referring the latter to the 
neighbourhood of Celogyne and Pholidota, Hexalectris to that of 
Bletia, Tipularia and Oreorchis to Phajinee. Ephippianthus, 
which Mr. Bentham refers to Liparis, seems to me quite distinct 
generically, and more nearly allied to Calypso. Oberonia has 
been added by Professor Reichenbach to the genus Malaxis; and 
in this he has been followed by a few botanists. To me, how- 
ever, it seems quite distinct in its habit, distichous leaves, and 
cylindrical spikes of flowers, which more resemble those of some 
Asiatic Microstyles than those of Malazis. I should class it, 
therefore, close to Microstylis. 
I believe the best and most natural way of classifying the 
Malaxidee is by the column. Malaxis, Microstylis, and Oberonia 
possess.a short thick column and flowers with the lip uppermost ; 
while in Liparis, Calypso, Ephippianthus, Corallorhiza, and Ore- 
orchis the column is long and slender, and the flowers erect. 
The relations of the two genera Microstylis and Liparis are 
very interesting. Both occupy nearly the same area, occurring 
in almost all the regions of the world, temperate and tropical, 
though the latter genus is far more abundant, and consequently 
somewhat more widely spread than the former. In all the spe- 
cies of each genus the characteristic form of the flower keeps 
true; so that there is never any doubt as to which genus any of 
the plants may be referred; but the vegetative organs show very 
distinct adaptive modifications in different climates and loca- 
lities. What is very remarkable is that the same modifica- 
tions in both genera seem to be characteristic of a region; 80 
that we find in the same region species of both Microstylis and 
