NOTES 437 
W. gracilis grows the quickest and soon overtops the others. 
Fine specimens can be seen at Villa Hindoue, and Villa St. Louis, 
at Garavan. Two small plants of W. sonore were sent by Mr. 
F. Ledien from the Royal Botanic Garden of Dresden in 1899 ; 
the tallest is now about 5 m. high and has a stem of 2°20 m. 
WIGANDIA. 
These form large bushes or small trees, and are of quick 
growth. W. caracasana is far more showy than W. wrens. It 
has large bunches of violet coloured flowers. The leaves are 
green on both sides, whilst those of W. wrens are tomentose 
underneath. Both come up very easily from seeds and suckers, 
and if once established in a place can only be removed with 
difficulty. They are sensitive to frost and easily damaged, but 
soon come up again from the roots. 
XANTHORRH@A ARBOREUM. 
This is our only representative of a very peculiar genus, com- 
prising eleven species, which form a conspicuous feature in the 
Australian landscape, and are known to the colonists by the 
names of “ grass trees” or ‘ black boys.” Our plant’is just begin- 
ning to form a stem, which may grow to several feet in height. 
There are some fine specimens in the Botanic Garden at Palermo. 
Yuccoas. 
Are perfectly at home here, although with a few exceptions 
they do not produce fruit. Y. alotfolua, which was introduced 
from Hyéres in December, 1867, and is now common in the 
garden, ripens fruit regularly every year; Y. elephantipes only 
does so occasionally. Some sixteen or twenty years ago Sir Thomas 
Hanbury introduced from America the moth Pronuba Yucca- 
sella, which is the only insect able to fertilize the Yuccas. But 
as the moth is so small and only visible at night during a few 
weeks of the year, nobody could ascertain whether the insect 
was really established. In 1897 and 1898, however, I found in 
the garden capsules of Y. flaccida, which exhibited the peculiar 
holes from which the larvee may have escaped. These capsules 
are still preserved in the Museum. Since then no other fruits 
have been observed on these plants. 
The most stately Yucca tree in the garden is Y. elephantzpes. 
This species has a remarkably thick or broad stem with a rough 
bark, somewhat like Beawcarnea. Its native country has not 
been ascertained, but according to Prof. Trelease it may come 
from the Atlantic coast of Nicaragua. In Guatemala, Honduras, 
&c., this tree is only known in cultivation. It is chiefly used as a 
rather poor hedge plant. In Guatemala, and probably also in 
Costa Rica, its flowers are sold in the markets, as they are eaten 
fried with eggs. 
We grow three forms of this species—one with very long 
and broad, often less canaliculate leaves, which is var. gegantea; 
