214 
Note. 
Epithema Horsfieldi , and all the six species of Monophyllaea, and says that ‘ if it 
should appear that the solitary leaves of these are really permanent cotyledons, it will 
be an additional proof of the very close connexion between different genera of the 
tribe/ Certainly in Monophyllaea the only foliar organs are the cotyledons. In 
adult plants the smaller cotyledon usually disappears, and I cannot see any bracts, 
even, in any of the specimens. Of the other plants of this habit mentioned by 
Mr. Clarke, Trachystigma , Platystemma , and Acanthonema have bracts, and of Didymo - 
carpus pygmaea Mr. Clarke says, ‘ Bracts none, or inconspicuous/ Epithema has 
often fully-developed normal leaves, and a large cup-shaped bract at the base of the 
flowers. A plant of very similar habit to Monophyllaea is Argostemma unifolium King. 
This has a succulent stem swollen tuberously at the base, and a large rounded leaf 
from the axil of which arise one or more peduncles. This Rubiaceous plant grows 
on rock faces, as Monophyllaea does. I have not had any opportunity of raising 
it from seed, but it is clear, I think, that in this plant the large leaf is not one of the 
cotyledons, for half-way up the stem, below the large leaf, is a pair of ovate scale- 
like leaves showing the presence of a node. These may be remains of cotyledons, 
but it is obvious that the upper leaf is not. Further, the large leaf is really one of a 
whorl of four leaves of which three are reduced to small size. Some allied species of 
Argostemma have a terminal whorl of four equal leaves, and in A. unifolium it appears 
that one of these leaves has developed to a large size while the others remain un- 
developed. 
A few other plants which inhabit these wet rock surfaces beneath the gloom of 
the forest seem also to have a tendency to reduce the number of leaves and increase 
the size of one, but in all of these it seems that these are true leaves and that it is 
only among the Gesneraceae that we find the cotyledons persisting and the true leaves 
not developed. 
Singapore. 
H. N. Ridley. 
