Another group of orchids having leek-like leaves are the 
rather plain-looking Microtis species. All have small, greenish 
flowers in a spike and some, such as M. porrifolia, are distributed 
abundantly throughout the park. Like the preceding genus 
Prasophyllam, they are often called Leek Orchids, and in Wes- 
tern Australia, Mignonette Orchids, though I must confess I have 
heard them called weeds. 
A very queer hot-weather orchid is Orthoceras strictum, the 
Horned Orchid. Usually coloured a dull brownish-green, it 
evades detection by growing among wiry grasses or rushes. 
Well known and loved by all, the brown and yellow Donkey 
Orchid, Dinris longifolia, and the Cowslip, D. pedunculata, are 
two worthy representatives of their genus in the park. Another 
yellow and brown spotted form, also called a Donkey Orchid, 
is D. maculata. A smaller, though very sweetly-scented, plant, 
D. palustris , deserves the name of Spice Orchid. 
Beautiful as many of these orchids are, few excel some of 
the Sun Orchids. Yellow and sweet-scented, the dainty little 
Rabbit-Ears is named Thelymitra antennifera. The Giant Sun 
Orchid, T. grandifl'^a, needs a warm, sunny day to show its 
purple blue beauty to perfection. Not so fastidious over the 
weather is the sweet-scented, mauve T. aristata. Even this species 
is seen at its best in bright sunshine. If we prefer pink shades 
we can find them also in the Sun Orchids. T. Macmillanii is a 
very beautiful salmon-red species. Two or three smaller- 
flowered species are also to be found in the pink shades. 
Including many species which have not been mentioned, 
fifty-six species have been found at the National Park. Many, 
of course, are rare and others are becoming rare, even though 
human depredations are restricted in this area. Perhaps the 
grazing of cattle and the rabbits can be held responsible for 
much of the damage done to the orchid flora. We must not 
forget the very disturbing influence that the introduction of 
alien plants has on our native terrestrial herbs. When we see 
the vivid Sparaxis and the tall Cape Tulip spreading so rapidly, 
we feel very concerned about the fate of our native plants before 
the onset of these vigorous invaders. Whatever the cause, it 
must be admitted and regretted that our orchids in the National 
Park are decreasing in numbers and variety, though the 
commoner species will most likely remain plentiful for some 
years yet. 
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