180 
FOXWORTHY. 
The true billian or Borneo ironwood was collected by me on the Island of 
Tawi Tawi recently (Bur. Sci. 10833, Jan. 19, 1910). It is there known by the 
name of tambulian, and is found in a strip of wet forest which shows very 
much the natural habitat of billian where it reaches its best development in 
Borneo. Also collected by W. Klemme, For. Bur. 22522, January, 1911. The 
wood has also been reported from one of the small islands just south of Mindanao, 
so it is probable that the species will be found to have a more extended range 
than is shown by the specimens cited. 
One of the small islands of the Sulu group has the name of Tambulian, but 
is said to have none of this tree on it at the present time. The known range of 
the species is now Sumatra, Banka, Billiton, Borneo, the Philippines. 
In Tawi Tawi, as elsewhere (T. & B. 1. c. 290; Miquel 1. e. 93; Beccari 1. c. 
566, 581; Foxworthy, 1. c. 452), different varieties of this tree seem to be 
recognized. Two different sizes and shapes of leaves are found and two different 
sizes and shapes of fruit. One form of fruit is almost spherical and another 
is long ellipsoid. Whether these are merely chance variations or specific dif- 
ferences I do not know; but, from the fact that they seem to occur under the 
same natural conditions, the differently shaped fruits being found together on 
the ground under the same tree, I incline to the former view. However, this 
is a question which can only be settled by a more detailed study of living trees. 
A very conspicuous feature of the tree habit, which I have not seen mentioned 
in descriptions of the tree, is that the young leaves have a beautiful coppery 
red color and are thin membranous in texture. This makes the tree recognizable 
at some little distance in the jungle. The bark is thin, gray and fissured, with 
fissures extending in a longitudinal direction. 
