294 Stapf — On the Sonerileae of Asia . 
ever, in his monograph enumerates all seven as distinct 
species, and puts them even into different sub-divisions. 
After a careful examination of the material in the Kew 
Herbarium, which includes all the type-specimens but one, I 
have come to the conclusion that all these species should be 
reduced to one species. 
5 . affinis was established on specimens collected by Col. 
Walker. They are perhaps a little more robust than those 
which were named by Wight and Arnott S. zeylanica , and 
their anthers are more attenuate. There are no other dif- 
ferences whatever. It was the shape of the anthers which 
evidently induced Thwaites, Clarke, and Cogniaux to follow 
Arnotts view concerning these two species. I, however, find 
differences in the shape and length of the anthers of the same 
amplitude within what is considered to be typical S. zeylanica. 
In fact, both species represent one unbroken series of forms 
varying with anthers 4-4*5 mm. long and produced into a 
slightly curved beak, to anthers not more than 1*5 mm. long, 
cordate-ovate and more or less obtuse. The specimens with 
smaller anthers are generally weaker, but some plants of 
this form, raised at Kew from seeds sent by Thwaites, 
maintained their short obtuse anthers, notwithstanding the 
luxuriant development of the vegetative parts. Both forms 
grow evidently together, as appears from the localities indi- 
cated on the labels. The species next described was 5 . gla- 
berrima , Arn. I have not seen the type-specimen of it which 
is preserved in Delessert’s Herbarium in Geneva. But Thwaites 
identifies it with his 6'. rostrata , whilst Cogniaux brings it 
close to 5 . rhornbifolia. These two species were brought into 
different divisions by Thwaites on account of the shape of the 
leaves, which he says are asymmetric in the former and sym- 
metric in the latter. This, however, is no reliable character. 
Symmetric leaves occur in 5 . rostrata , as well as in S', affinis 
and S', zeylanica. and on the other hand S. rhornbifolia has 
also occasionally some asymmetric leaves, just like those which 
prevail in S. rostrata. In fact, the difference of both of them 
is limited to the more robust habit and the larger leaves in 
