May-JUNE, 1919] THE ORCHID REVIEW. 73 
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| AUSTRALIAN ORCHIDS. 9 
HE Orchids of Australia are numerous and interesting, and some’ of 
them are familiar to our readers from the beautiful coloured drawings 
of Fitzgerald, though few of the terrestrial kinds are known in European 
gardens. A few interesting details respecting them have been sent by Dr. 
R. S. Rogers, of Adelaide, who has long made a study of the group, and 
has described a number of new species. He remarks that the Orchids of 
South and West Australia are entirely terrestrial.. The majority of the 
species re-appear in the same localities with clockwork precision every season, 
though often in greatly reduced numbers in years of drought. On the other 
hand, he has noticed that after extensive bush fires, which frequently sweep 
the hills, they become very prolific, though whether this is due to the 
eradication of the ranker competing vegetation, to the stimulation of the 
tubers by heat, to some chemical change in the soil by combustion, or to 
new and favourable conditions for the propagation of some friendly fungus 
he is unable to say. The thorough way in which some of these fires clears 
the scrub of all undergrowth makes it rather surprising that this should 
largely re-appear within a few weeks or months. The resting period of some 
of the tubers is very prolonged, in some cases extending through many 
Seasons, and he has occasionally potted up tubers which from some cause 
have not vegetated for five orsix years. Three interesting cases are mentioned 
in this connection. 
“Caleana maior is a rare plant in South Australia, and the very few . 
localities in which it is to be found are known to me. The summit of Mt. 
Lofty is a place which I and my friends have constantly visited and searched 
for many years, and this Caleana had never been found within many miles’ 
of it, yet one season a botanical friend discovered quite a number of plants 
there, and brought them to me for determination. Had the tubers survived 
for a long period of time and then vegetated, or had the seeds a very long 
vegetating period, extending over many seasons ? That is about ten seasons 
ago, and though we have looked for it carefully every year we have seen no 
trace of it since. 
“Prasophyllum gracile, Rogers, was also considered by me @ rare species 
and so far as I knew it was only to be found in one. locality, about fifty 
miles from Adelaide. And yet one season, after a most. devasting fire, it 
appeared in a much frequented locality in our hills near‘the city, in countless 
Numbers. That was, I think, in the year 1913, and although I have made 
the most diligent search over the hills in every subsequent season | have 
failed to find even:a trace of it. ee cee 
