Editing Macrozamia communis (section)

===Habitat Conditions: ===
''M. communis'' grows prolifically, in some areas abundantly, on the south coast of New South Wales and to a slightly lesser degree on the central coast, north of Sydney.
''M. communis'' reaches its maximum population density on stabilised sand dunes in close proximity to the ocean. It also grows in dense stands on steep hillsides and slopes of near coastal ranges.
''M. communis'' grows in areas of woodland, open forest or tall open forest. On the south coast it grows principally under a canopy of ''Corymbia maculata'' (previously ''Eucalyptus maculata''); where ''C. maculata'' (the "spotted gum") is present, ''M. communis'' is normally the dominant understorey plant, although scattered Banksia sp are often present. On the Central coast, the principal canopy cover is provided by ''Angophora costata'' (the "Sydney red gum").
As a general rule (thought this is not an ironclad rule) ''M. communis'' usually forms a subterranean caudex on coastal sand dunes (due to the action of contractile roots), whereas in shallow soils and on quartzite and sandstone ridges it tends to form an aerial extension of the caudex or a short columnar trunk.
Despite the above comment, however, the old adage that the only consistent factor about cycads is their inconsistency applies to this species, as trunked specimens are common in some stands that have formed on coastal sand dunes.
Near Batemans Bay on the south coast, ''M. communis'' is ubiquitous and can be found growing in numerous dense and extensive stands. There are literally thousands upon thousands of plants growing within a 20 kilometre radius of Batemans Bay (albeit that many stands have been decimated in the name of progress to make way for homes,
farms or tourist developments).
 
In some dense stands on the south coast of New South Wales, ''M. communis'' grows in such abundance that, in order to move through a stand, it is necessary to force your way through the overlapping fronds of numerous closely growing plants and simultaneously protect your eyes from the sharply-tipped pinnae (on fronds which can reach up to 2.4 metres above ground level, from a subterranean caudex).
The density of plants in some of the above stands is such that the ground is often totally obscured by the multiple layers of fronds and it is virtually impossible to see where, or on what, you are treading as you move, with great difficulty, through the crowded plants.
No other cycad in New South Wales (or to our knowledge in Australia) has a population density of the same magnitude as ''M. communis''.  In this respect, despite the fact that we have described
''[Lepidozamia peroffskyana]'' as growing "in abundance" with "adult plants growing so prolifically that the fronds of numerous plants growing very close together actually overlap each other", the population density of
''M. communis'' in certain areas on the south
coast of New South Wales far exceeds the density of the most populous stands of
''L. peroffskyana'' that we have seen.
''M. communis'' increases significantly in size as it moves southward. Not only does the overall size of the plants increase but there is a corresponding increase in the size of both cones and seeds. We have been advised by Keith Boyer, a New Zealand cycad enthusiast, that plants grown from seed collected near Batemans Bay grow much better in the temperate climate of New Zealand than plants grown from smaller seeds collected from smaller plants near Gosford (on the central coast).