THE WESTERN AUSTRALIAN CHRISTMAS TREE. 
NUYTSIA F LOB IB UN D A (THE CHRISTMAS TREE)— ITS 
STRUCTURE AND PARASITISM. 
By D. A. Herbert, B.Se., Economic Botanist and Plant Pathologist 
to the Western Australian Government. 
{Head 8th April , 1919.) 
Nuytsia floribunda, the Christmas Tree, is perhaps the most 
interesting member of the flora of Western Australia. It is con- 
fined to the South-Western division of the State, being found from 
the Murchison River round to Esperauee. The tree finally reaches 
the height of 30-35 feet, and frequently two or more trunks arise 
together. At Christmas time the tree is a brilliant blaze of orange 
flowers, which are borne on dense racemes at the ends of the 
branches. The immense development of flowers is all the more 
remarkable since so few fertile seeds develop. Many trees do not 
develop a single seed; others may develop a number — a very small 
number in comparison with the tremendous number of flowers — 
but very few of these are fertile. Whether fertile seeds will pro- 
duce mature plants is a question which will be discussed later in 
this paper. 
The failure of the tree to produce much seed may be the direct 
result of the large production of blossom. A great deal of stored 
food material is used up in the flowering period and in Nuytsia 
where blossom is so abundant the resources are too much depleted 
to provide enough food material for the maturing of the fruits. 
This is borne out by the condition of the mucilage in the plant 
before and after flowering. Before flowering the mucilage canals 
are full of a milky .fluid in such quantity that quite a large amount 
is exuded when a. root or branch is broken or cut. 1 his rapidly 
coagulates and blackens on exposure to air. It is very palatable 
to some animals, especially pigs, which root up the roots for yards 
if they are close to the surface. During the flowering period it 
decreases rapidly in amount and loses its milkiness, until at the 
period when the tree should be fruiting the exudation from a 
broken root or branch is almost nil. 
That this non-production of fruit is probably due to the large 
amount of blossom formed is also borne out by the fact that the 
same phenomenon occurs in the case of cultivated trees, such as 
th' -pple and the pear. Very frequently such trees have a tre- 
mendous development of blossom which results in hardly a single 
