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[[File:Cycas_pruinosa.jpg|frame|Figure 1. ''C. pruinosa'' near Kununurra, WA.]]
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The specific name, pruinosa, means covered with powder and
aptly describes the blue-white ovules of this plant.
Officially named in 1978, this unique ''Cycas'' is
probably the nearest relative to the south-east Asian species
of ''Cycas''. J.R. Maconochie persistently mentions the pronounced
revolute margins of the pinnae and although this does not
make it definitely allied, my photos looking down into the
female seeds show other similarities. For instance, the very
ferruginous nature of the end of the megasporophyll. It is
pinnate, dentate and has between 20 to 30 soft teeth of 25mm
long. The apex does not sharply crown in the female as in
''Cycas media'',
but it is rather obtuse and to a point. Opening slowly it
reveals the green four to a megasporophyll ovules with
slightly oval shape. They mature to bluish-white and heavily
dusted with powder. The seed development has
''C. revoluta'' similarities.

Furtherto this, the stout
trunk which is from 60cm to 2.0m in height, is crowned with
arching fronds, distinctly curved from the apex and
V-shaped in cross-section. The colour of the pinnae and
glaucous rachis is bluish grey in most specimens, but leaning
toward the blue. The male cones are narrow, rather deltoid
and about 50.0-60.0cm long. The heavily powdered female
seed is about 40.0mm long and 35.0mm in diameter. Mature
fronds are approximately 1.0m long and with an average of
120 pairs of pinnae on each rachis.
The newly emerging megasporophylls are rusty brown and when
fully extended recurve backward having a coating of blue
white powder on all seed ovules. The formation of seed and
toothed megasporophylls in the apex of the female crown is
very interesting and again has some likenesses to the exotic
''C. revoluta''.
Good stands of this species can be found on the hillside
above the car park at Lake Argyle in Western Australia. It is
also found in valleys and surrounds in the area. The habitat
seems to occupy an area from Argyle through Kununurra to the
mouth of the Ord River districts, plus sightings mentioned by
Maconochie being The Grotto, Carr Boyd Ranges, Kununurra,
Ivanhoe Station, Middle Springs, Deception Ranges, south to
Hall's Creek and Springvale Homestead. Sightings have been
made in the sloping hill country. Up to the time of this
writing this species is not common in cultivation. One very
important feature not previously mentioned is the existence
of two distinct colour forms of this ''Cycas'' growing in
basically the same areas; one a definite glaucous blue, the
other rather grey-green.

The Napier Ranges are on the western edge of the
Kimberleys, Western Australia, and a few hundred kilometres
from the Argyle Gorge country. Nevertheless, there exists
within this range a substantial colony of ''Cycas'' that
with only a few minor differences is at least a form of
''Cycas pruinosa''.
The basic geology of the area is limestone and in at least
one situation an entire hillside has no other prominent
vegetation except a large colony of these cycads. Spinifex
provides the ground cover throughout much of this particular
habitat and the plants grow between the exposed boulders and
ridges of this very ancient reef. Apparently the exposed
boulders have been weather-worn, lichen covered and badly
discoloured by time. First reports were that the rocks were
basalt but this has since been proven incorrect.
Both blue and green forms of this ''Cycas'' are evident
as has been seen in the Argyle and Ord River sightings. The
largest plants observed are about 2.5 m tall and with stout
caudices.
Ron Smith, nurseryman, mentions the pronounced visual
similarities these plants have to the exotic
''Cycas revoluta'';
This being even more so in the green
form. Apart from the now well known similarities of the
narrow revolute pinnae and the 'nesting' crown habit of the
megasporophylls, this ''Cycas produces'' many offshoots
around the base of the caudex as is common in such exotic
species as ''Cycas revoluta'',
''C. circinalis'' and
''C. rumphii''. Much of the seed
now distributed throughout the nursery trade has come from
this source and already the blue or green fronds are visible
in resultant seedlings.
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[[File:Cycas_pruinosa1.jpg|frame|Figure 2. Male cones.]]
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[[File:Cycas_pruinosa2-01.jpg|frame|Figure 3. Cultivated plant, Katherine, NT.]]
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===Contributed by: ===
L. P. Butt<br/>
D. Stallard (Figures 1&2.)<br/>
Gary Beaumont (Figure 3)<br/>

===External Links:===
[https://www.cycadlist.org/taxon.php?Taxon_ID=189 World List],
[https://www.iucnredlist.org/details/full/41993/0 IUCN],
[https://www.jstor.org/action/doBasicSearch?Query=Cycas+pruinosa JSTOR],
[https://www.trebrown.com/plant_info.php?species=Cycas+pruinosa Trebrown]
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[https://www.google.com/search?q=%22Cycas+pruinosa%22&num=10&sa=Google+Search Google],
[https://images.google.com/images?q=%22Cycas+pruinosa%22&hl=en&btnG=Google+Search GoogleImages],
[https://www.flickr.com/search/?q=Cycas+pruinosa Flickr],
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[[Category:Cycas|pruinosa]]
[[Category:Cycad|Cycas_pruinosa]]

Cycas pruinosa - Revision history

Pacsoa: 1 revision imported

P>Pacsoa at 21:40, 23 September 2024