34 
The Queensland Naturalist June, 1939 
SUBTERRANEAN PLANT LIFE. 
(Presidential Address delivered before the Queensland 
Naturalists * Club, February 20th, 1939.) 
By D. A. Herbert, D.Sc., Queensland University. 
Life in a plant community is a continual struggle 
against environment ; and in that environment other 
plants are often the most relentless competitors. In 
cultivation plants from the most varied habitats are 
brought together, and freed from competition, they 
flourish under conditions very different from those 
under which they grew in nature. Certainly there are 
great differences in the requirements of different species 
from different soils and climates, but soils and climates 
are not the only factors in the distribution of species. A 
plant may be occupying a habitat that is by no means 
ideal, because it is excluded by competition from the 
type of country most favourable to its growth and re- 
production. In other words, the conditions under which 
it grows in nature are not necessarily the ideal condi- 
tions for its existence, any more than a kerosene tin hut 
is the ideal residence for a man forced into relief work 
by competition on the labour market. 
In coastal Queensland rain forest often grows in the 
moist gullies and on the more retentive soils, leaving 
the drier positions to the Eucalypts. It is not that the 
Eucalypts necessarily thrive better in the drier posi- 
tions; many of the most straggly species develop into 
fine specimens when they are given better conditions 
from which they are excluded in nature. The Western 
Australian red flowering gum ( Eucalyptus ficifolia) 
grows in twisted thickets near the coast to the west of 
Albany, but apart from its brilliant flowers, is a most 
unprepossessing tree. Yet given reasonable attention in 
a garden or in an avenue, it develops into a fine, shapely 
specimen. 
The characters which enable a plant to tolerate or 
flourish in some particular environment constitute its 
adaptations to those conditions. There are many charac- 
ters which are obviously of advantage, for example, the 
breathing apparatus of mangrove roots which solve the 
problem of aeration in a soil which is constantly water- 
logged, the high osmotic pressure of many plants of 
saline regions, and the rapid growth of climbing plants 
in the poorly lighted rain forest. These are some of the 
devices which enable their possessors to survive where 
