14 
The Queensland Naturalist. 
July, 1921 
staurolite (Cloncurry) ; grass stone or sagenite (Stan- 
thorpe) ; malachite (Chillagoe) ; cairngorm (Stanthorpe) ; 
diamonds (Anakie and Stanthorpe) ; pink sapphire 
(Anakie) ; ruby (Russell goldfield) ; Oriental amethyst 
(Russell goldfield) ; Oriental moonstone and cat’s-eye- 
(Anakie). 
o 
FOUR NOTABLE NATIVE PLANTS. 
By C T. WHITE, F.L.S., Government Botanist. 
A VARIEGATED BOX TREE. 
While rambling through some forest country near 
Brisbane, Mr. J. A. Alder recently came across a beautiful 
variegated form of the Brisbane Box, or Scrub Box 
( Tristania confer ta ), the variegation consisting of about 
half the leaf being of a golden tint in place of the ordinary 
green colour. I had not seen this condition in the Box 
before, but it has been recorded for several native 
plants, among others being the Brown Kurrajong 
( Commer sonia echinata ), the Cockspur Thorn ( Cudrania 
javanensis), the Walking-Stick Palm ( Bacularia mono- 
stachva) and the Coast Hibiscus ( Hibiscus tiliaceus). 
To understand variegation, it may be explained that 
the cells of plants contain numerous small bodies called 
plastids, of which three kinds occur. In the exposed parts 
of plants, such as the leaves and young stems, the plastids 
are green, and in consequence are termed chloroplasts ; 
they contain chlorophyll, which is the characteristic 
green colouring matter of plants. In underground parts 
•and deep-seated tissues the plastids are colourless, and 
receive the name 1 leucoplasts; in petals and often other 
floral parts the plastids contain various colouring matters, 
and are hence termed chromoplasts. 
These three kinds of plastids are convertible one- 
into the other. The leucoplasts of underground parts, 
potato tubers for instance, develop chlorophyll when 
exposed to the light; similarly, the chloroplasts of such 
plants as the endive and celery are artificially converted 
into leucoplasts by the gardener; the chloroplasts of 
green unripe fruits develop into chromoplasts as the fruit 
ripens: and those of the cells of young leaves may change 
into chromoplasts, producing the well-known autumn 
tints. 
Variegation in leaves is hence due to the fact that in- 
certain parts, in place of the ordinary green plastids or 
