Macrozamia reducta

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Figure 1. M. reducta.

Contents

Introduction:

Macrozamia reducta is a medium sized (Section Macrozamia) cycad that is endemic to New South Wales. It normally has a subterranean caudex; though, on rare occasions, it produces a short emergent trunk.

History:

M. reducta was identified as recently as 1998 by Ken Hill and David Jones. It is a segregate of M. communis and, in effect, can be broadly described as a size-reduced M. communis. It was named after its reduced stature in relation to M. communis. It was previously known, by cycad enthusiasts, as either the "dwarf communis" or the "Macrozamia Cessnock dwarf."

Distribution Range:

The distribution range for M. reducta extends from the Newcastle/Cessnock area westward to near Mudgee, and then south to Glen Davis. It is thus the only New South Wales cycad which has a distribution range that extends from coastal and near coastal areas to the inland slopes of the Great Dividing Range.

Habitat Conditions:

M. reducta grows abundantly in several thickly populated stands the Cessnock region on flat, poor quality clay-based soil, under a eucalypt canopy with a thick, bushy Bursaria sp understorey. In inland regions, it grows on undulating hillsides in poor quality, rocky soil. Inland plants of this species generally have less fronds and are smaller than those plants which grow in the Newcastle/Cessnock area " and they do not form thickly populated stands.

Climatic Data:

Cessnock (elevation 62 metres) has an annual average rainfall of 769 mm (spread over 102 rain days) with winter minimum and summer maximum temperatures (reached at least once per week in July and January) of -0.4 and 36.1° C. respectively. Frosts occur on an average of 28 days per year.

Figure 2. M. reducta.

Rainfall Patterns:

Over 60% of the annual rainfall at Cessnock falls during summer and autumn. The percentage seasonal rainfall pattern is as follows: Summer: 34%, Autumn: 28%, Winter: 15% and Spring: 23%.

Principal Characteristics:

The principal characteristics of M. reducta are as follows:

  • a subterranean caudex; or, rarely, a short emergent trunk.
  • dark green coloured fronds
  • initially upright fronds, that spread with age
  • an untwisted rhachis
  • entire and sharply-tipped pinnae which are angled forward (at an angle of 45 degrees to the rhachis) and which extend in a horizontal plane from the rhachis
  • a prominent creamy-whitish callous at the point where the pinnae join the rhachis
  • pinnae which reduce to spine-like appendages, towards the base of the fronds
  • seeds with reddish coloured flesh.

Fronds:

M. reducta can have up to 40 fronds that are initially a mid-green colour, but which change to a dark green colour with age.

Pinnae:

The pinnae callouses are normally a prominent creamy-yellowish colour, but this colour tends to fade with age.

Cones:

Female plants usually produce mostly a single cone, but occasionally 2 cones are produced. Male plants produce from 1-4 cones. This species cones regularly in coastal and near-coastal areas, but coning occurs much less frequently in inland areas.

Figure 3. M. reducta - female cone in habitat (fully developed).

Hybridisation:

In the Cessnock area, where large stands of both M. reducta and M. flexuosa occur, M. reducta hybridises with M. flexuosa. Likewise, in the Mudgee area, hybrid plants can be found where M. reducta and M. secunda grow in close proximity to each other.

Affinities:

In virtually every respect, M. reducta is a miniaturised M. communis. Compared with M. communis, it has shorter fronds, shorter pinnae, smaller cones and smaller seeds.

Figure 4. M. reducta male cone.
Figure 5. M. reducta female cone (not fully developed).
Figure 6. M. reducta distending male cone in habitat.
Figure 7. M. reducta twin male cones (plus one adjacent spent male cone).
Figure 8. M. reducta in habitat.
Figure 9. M. reducta in habitat.
Figure 10. M. reducta in habitat.
Figure 11. M. reducta in habitat.
Figure 12. M. reducta in habitat.
Figure 13. M. reducta in habitat.
Figure 14. M. reducta in habitat.
Figure 15. M. reducta in habitat.
Figure 16. M. reducta close-up of frond displaying M. flexuosa characteristics.

Synonymy:

Macrozamia 'Cessnock dwarf'

Distribution & Habitat:

Found in dry sclerophyll woodlands on sandy soils over sandstone on ridges, from the western suburbs of Newcastle west almost to Mudgee, New South Wales.

Description:

This is a member of the M. communis complex, so it is very similar in appearance to that species, but it is smaller; in both leaf size, cone size (male and female) and seed size. It has up to 40, bright green to deep green, semiglossy leaves, flat in section, up to 150cm long, with up to 120 leaflets, up to 320mm long, and 9mm wide. The rachis is straight, not spirally twisted.

Culture:

Prefers a lightly shaded, well drained position. Drought and frost tolerant.

Figure 1. M. reducta at Quail Botanical Gardens.
Figure 2. M. reducta
Figure 3. M. reducta


Contributed by:

Paul Kennedy and Craig Thompson (Text and Figures 1-7)

External Links:

Cycad Pages, IUCN, JSTOR, Trebrown

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