Kraenzlin was unable to discover a well-preserved flower 
on the type sheet except in the bud stage when preser- 
vation is often better. This would explain the short per- 
ianth members since it is a well-known fact that there is 
considerable growth in length as the flower develops. 
There is, however, a possibility that Diimmer 4437 1s a 
mixture of two species and that Kraenzlin’s type differs 
from the material seen. 
So far as can be judged from the description, Diapha- 
nanthe subclavata (Rolfe) Schltr. (Angraecum subclava- 
tum Rolfe in Bolet. Soc. Broter. 9 (1892) 140) seems also 
to be referable to D. bidens. Unfortunately no specimen 
could be discovered in the herbaria at the British Mu- 
seum or at Coimbra. Admittedly Rolfe described the 
pollinia originally as having only a single stipe, but he 
stated that the species is allied to Listrostachys ashanten- 
sis. However, in the Flora of Tropical Africa (vol. 7, p. 
160) he transfers the species to Listrostachys which, as 
understood by him there, possesses two separate stipites 
in the pollinarium. D. didens has been recorded from 
Fernando Po and there seems no reason why such a 
widely spread species should not also occur in Sao ‘Tomé. 
Arrangement of the specimens in a geographical se- 
quence from west to east shows that those occurring to 
the west of the Cameroons Mountain have on the whole 
shorter and broader leaves than those to the east and 
south. There is no absolute distinction, however, mod- 
erately long-leaved forms being found in Sierra Leone 
and short-leaved ones in Gabon. The flowers in the 
‘‘Congo’’ group are on the whole slightly larger and the 
spur relatively shorter than in gatherings from *‘Upper 
Guinea,’” but again there is no hard and fast line of de- 
marcation. With regard to variations in the labellum, 
which have been used by some authors for differentiating 
purposes, it is obvious that considerable variations occur. 
[ 100 | 
