Editing Cycas silvestris

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[[File:Cycas_silvestris.jpg|frame|Figure 1. ''C. silvestris'']]
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''Cycas silvestris'' was described by Ken Hill in his preliminary account of the genus ''Cycas'' in Queensland(Hill 1992).
The species was stated to occur on Cape York Peninsular in the vicinity of the Olive River estuary where it grows in
closed forests (rainforests) on old beach dunes. The type specimen for ''C. silvestris'' was collected by J.R. Clarkson
and V.J. Neldner in 1990, both botanists with the Queensland Herbarium. The first specimens of ''C. silvestris'' 
to be collected, were done so concurrently by B.P.M. Hyland, and L.J. Webb & J.G. Tracey, all then botanists with CSIRO,
on 12 September 1974. ''Cycas silvestris'' is perhaps one of most poorly known of the Queensland species of ''Cycas''.

Hill had not seen male cones when he described the species, and apart from 
the line drawings of frond segments and megasporophylls that accompany his 
description, there are no published photographs in the literature. ''C. silvestris''
is also unusual amongst the Queensland ''Cycas'' species, as it produces 
a very small male cone that is 11-13 cm long by c. 5 cm diameter with 
microsporophylls 20-22 mm long by 11-13 mm wide, which is considerably 
smaller than for the other Queensland species enumerated by Hill (1992).

The seeds are also more variable than given by Hill, with considerable differences 
in shape and size. From a range of about two hundred mature seeds examined in the field, 
the size range is 30-39 mm long and 25-32 mm wide, with some nearly globose in shape, 
although most are ovoid as stated by Hill.
''Cycas silvestris'' is quite a spectacular cycad and it is not uncommon to encounter 
individuals up to 7m in height. These are usually single-headed, although some are multi-headed, 
probably because of past damage to the growing tip. Some plants are more or less decumbent, 
perhaps as a result of storm damage causing the plants to be partially uprooted at some time in the past (Fig. 2). 
The foliage is glossy mid-green, and the plants are reminiscent of many taxa in the 
''[[Cycas rumphii]]'' Miq. complex (Hill 1994).
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[[File:Cycas_silvestris1.jpg|frame|Figure 2. Partially decumbent individual of ''C. silvestris''.]]
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[[File:Cycas_silvestris2.jpg|frame|Figure 3. Trunk morphology of ''C. silvestris''.]]
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Plants of ''C. silvestris'' occur generally as small
groups or "cycad groves", often with a number of old mature
specimens, some smaller plants an innumerable small seedlings.
In nearly all instances the plants grow within the canopy of
dry rainforest (''Araucaria microphyll'' vineforest) that is
characterised by emergent hoop-pines (''Araucaria cunninghamii'')
and a rich diversity of other trees and shrubs,
many also endemic to the Olive River area. This community
occurs on deep sand - dunes immediately behind the foredune
and for up to 2 km inland. The cycads are patchily
distributed in this community, but overall are quite common
in the area.

Hill (1992) stated that the conservation status of the
species was 2V, i.e. vulnerable and known from a range of
less than 100 km. It now appears that the distribution range
of ''C. silvestris'' may be far greater than previously
thought, as plants that appear identical to those at the type
locality, have been found in a southern disjunct population
near the Nesbit River.

While ''C. silvestris'' is abundant at the type locality,
it still does not occur in a conservation reserve on Cape
York Peninsula and is currently listed as VULNERABLE and
subject to collector pressure (Forster 1996). Despite the
difficulty of access to the habitat, there is evidence of
poaching of plants (both in 1991 and in 1996), although there
is no evidence of large numbers of caudices in the cycad
trade. A limited number of seed and seedlings have been
available in the last few years, although future offerings of
this cycad will be subject to Department of Environment
regulations (Forster 1996).

Cultivation of ''C. silvestris'' should be straightforward and
similar to methods that produce success for species from Asia
and the Western Pacific. In habitat the plants grow in white
beach sand with organic matter and experience excellent
drainage. Plants are tolerant of shading, although many are
in full sun and seem to cope with this. Root and caudex
development is extensive and seedlings should be given plenty
of pot-room. There does not seem to be a marked deciduousness
and flushing of the foliage as is encountered with many of
the Australian ''Cycas'' species from drier habitats.

===Acknowledgements===
Thanks to Bruce Gray for the photographs reproduced herein,
and to Peter Bostock for comments on the note.

===References===
Forster, P.I. (1996). A preliminary assessment of cycad
conservation and diversity in Queensland, Australia.
Encephalartos 46:8 -18.<br/>
Hill, K.D. (1992). A preliminary account of
''Cycas'' (Cycadaceae) in Queensland. Telopea 5: 177 - 206.
Hill, K .D. (1994). The ''Cycas rumphii'' complex
(Cycadaceae) in New Guinea and the Western Pacific.
Australian Systematic Botany 7:543 - 567.

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[[File:Cycas_silvestris3-01.jpg|frame|Figure 4. Cultivated specimen, Katherine, NT.]]
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===Contributed by: ===
Paul I. Forster, Queensland Herbarium.<br/>
Gary Beaumont (Figure 4).<br/>
Reproduced from '''''Palms & Cycads''''' No 52&53, Jul-Dec 1996.<br/>


===External Links:===
[https://www.cycadlist.org/taxon.php?Taxon_ID=215 World List], 
[https://www.iucnredlist.org/details/full/41960/0 IUCN],
[https://www.jstor.org/action/doBasicSearch?Query=Cycas+silvestris JSTOR],
[https://www.trebrown.com/plant_info.php?species=Cycas+silvestris Trebrown],
[https://keys.trin.org.au/key-server/data/0e0f0504-0103-430d-8004-060d07080d04/media/Html/taxon/Cycas_silvestris.htm ATRP]
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[https://www.google.com/search?q=%22Cycas+silvestris%22&amp;num=10&amp;sa=Google+Search Google],
[https://images.google.com/images?q=%22Cycas+silvestris%22&amp;hl=en&amp;btnG=Google+Search GoogleImages],
[https://www.flickr.com/search/?q=Cycas+silvestris Flickr],
<p>
[[Category:Cycas|silvestris]]
[[Category:Cycad|Cycas_silvestris]]