Few cycads have had their conservation status revised as dramatically as Macrozamia flexuosa. In 2010, the IUCN Red List classified it as Endangered, estimating just 2,500–10,000 mature individuals. In 2019, botanist Stephen Bell published a landmark study in Cunninghamia that changed the picture entirely: using 588 point records, high-resolution vegetation mapping, and interpolation across 175,000 hectares of the Hunter Valley, he estimated the total population at between 1.74 million and 43.5 million individuals — conserved in at least 14 reserves. Bell recommended downgrading the species to Near Threatened (NT). This is a cycad that went, on paper, from the edge of extinction to one of the most abundant in Australia — not because anything changed in the field, but because someone finally counted properly.
Endemic to the Hunter Region of New South Wales, from Bulahdelah south to Wyong and inland to Belford, Macrozamia flexuosa is a small, subterranean-stemmed Macrozamia (section Parazamia) species with strongly spirally twisted leaves, bright glossy green pinnae with involute margins, and cones so small they could be mistaken for ornamental pine cones. It is the only Parazamia species in the Hunter Valley, where it co-occurs with — and hybridises with — the straight-leaved Macrozamia reducta and Macrozamia communis.
Quick Facts
| Scientific name | Macrozamia flexuosa C.Moore |
| Family | Zamiaceae |
| Origin | Hunter Region, New South Wales, Australia (Bulahdelah–Wyong–Belford) |
| Adult size | Acaulescent; stem subterranean, 8–20 cm diam.; 1–6 leaves, 45–100 cm long |
| Hardiness | −3 to −5 °C (27 to 23 °F) / USDA zone 9b (zone 9a with protection) |
| IUCN | Endangered (EN) — but Bell (2015, 2019) recommends Near Threatened (NT) |
| CITES | Appendix II (all cycads) |
| Cultivation difficulty | 3/5 |
Taxonomy and Nomenclature
Macrozamia flexuosa has had a complex taxonomic journey through three different names before settling at species rank:
1883: Charles Moore described the plant from a specimen collected by Ernst Betche in January 1883 at Limeburners Creek, near Karuah (north of Newcastle). It was originally treated as a variety of Macrozamia spiralis.
1959: L. A. S. Johnson transferred it to Macrozamia pauli-guilielmi subsp. flexuosa, recognising its affinity with the Queensland Pineapple Zamia but not granting it full species rank.
1998: Ken Hill raised it to species rank as Macrozamia flexuosa C.Moore in the Flora of Australia volume 48.
Etymology: the specific epithet flexuosa (Latin: “flexuous, bent, winding”) refers to the strongly spirally twisted rachis — the defining character of the species.
Section: Parazamia — the small, subterranean-caudex, twisted-leaf group. Within Parazamia, M. flexuosa is closely related to Macrozamia pauli-guilielmi (Queensland) and is morphologically closest to it — but geographically separated by ~700 km and ecologically differentiated.
Synonym: Macrozamia pauli-guilielmi subsp. flexuosa (C.Moore) L.A.S.Johnson.
Morphological Description
Macrozamia flexuosa is a small, dioecious, evergreen cycad — compact, ground-hugging, and defined by its twisted, glossy foliage.
Stem: entirely subterranean, 8–20 cm diameter. This is among the smallest caudices in the genus.
Leaves: 1–6 in the crown, forming a sparse, erect rosette. Mature leaves are 45–100 cm long. The petiole is long, ± terete (rounded in cross-section), 20–35 cm long — a diagnostic character that distinguishes M. flexuosa from M. pauli-guilielmi, which has shorter, flattened petioles.
Rachis: strongly spirally twisted — though typically less intensely than the ten 360° rotations per metre seen in M. pauli-guilielmi.
Pinnae (leaflets): 80–150 per leaf, bright green, highly glossy to semi-glossy, strongly discolorous (darker above, markedly paler beneath). Longest pinnae 17–30 cm long, 3–7 mm wide. The key diagnostic character: pinnae are lax (not rigid), mid-green, with involute margins (margins curved inward). Basal pinnae are not reduced to spines — a section Parazamia character that separates it from the co-occurring M. reducta and M. communis (both section Macrozamia, which have basal spines).
Male cones: small — 15 cm long, 4.5 cm wide; sporophyll spines 0.2–1 cm.
Female cones: ovoid, 10–16 cm long, 7–11 cm diameter; spines 0.5–3.5 cm.
Seeds: ovoid, 2.4–2.7 cm long, 1.9–2.3 cm wide, red when ripe. Field observations at Columbey National Park show evidence of partial seed consumption by mammalian predators.
Comparison with Related Species
| Character | M. flexuosa | M. pauli-guilielmi | M. reducta | M. communis |
|---|---|---|---|---|
| Section | Parazamia | Parazamia | Macrozamia | Macrozamia |
| Rachis | Strongly twisted | Extremely twisted (~10 × 360°/m) | Not twisted | Not twisted |
| Basal pinnae | Not reduced to spines | Not reduced to spines | Reduced to spines | Reduced to spines |
| Petiole | Long, ± terete | Short, flattened | 13–30 cm, flat | 12–60 cm, flat |
| Pinnae colour | Bright green, glossy | Pale green, dull, yellowish beneath | Bright–mid green, semi-glossy | Dark green, rather dull |
| Pinnae margins | Involute | Flat to concave | Flat | Flat |
| Female cone length | 10–16 cm | 9–12 cm | 16–23 cm | 20–45 cm |
| Distribution | Hunter Region NSW | Wide Bay QLD | Newcastle–Mudgee NSW | Coastal NSW (Taree–Bega) |
| Hybridisation | With M. reducta & M. communis | None documented | With M. flexuosa & M. secunda | With M. flexuosa |
The involute leaf margins, the terete (rounded) petiole, and the glossy bright green colour together form the diagnostic triad that separates M. flexuosa from all other twisted-leaf Macrozamia. The M. pauli-guilielmi article on succulentes.net noted that the two species are morphologically closest — but M. flexuosa is distinguished by its “longer, less flattened petioles” and “broader, brighter green, glossy leaflets.”
Hybridisation
Macrozamia flexuosa hybridises with two species from a different morphological section:
- With Macrozamia reducta (section Macrozamia) in the Cessnock area, where large populations of both species co-occur — notably in Werakata National Park, where M. flexuosa predominates in the southern portions and M. reducta co-occurs.
- With Macrozamia communis (section Macrozamia) on the North Coast (NC) of NSW, as noted by PlantNET.
These inter-sectional hybrids are scientifically significant. They cross the morphological boundary between Parazamia (twisted rachis, no basal spines) and Macrozamia (straight rachis, basal spines), demonstrating that the sectional division — while useful taxonomically — does not represent a complete reproductive barrier. The phylotranscriptomic analysis of Habib et al. (2022) supports this, showing that the traditional sectional division is inconsistent with the molecular phylogeny.
Distribution and Natural Habitat
Macrozamia flexuosa is endemic to the Hunter Region of New South Wales — from Bulahdelah (north) to Wyong / Lake Macquarie (south), and inland to Belford (near Singleton). The type locality is Limeburners Creek, near Karuah.
Extent of occurrence: 6,319 km². Area of occupancy: 696 km² (Bell 2019).
The species occurs most frequently on Permian-aged sediments (Newcastle Coal Measures), but also on older Carboniferous sediments, younger Triassic Narrabeen sandstone, and Quaternary substrates. The principal vegetation communities are:
- Lower Hunter Spotted Gum–Ironbark Forest (41% of records) — the dominant habitat, preferring conglomerate-derived soils.
- Kurri Sands Swamp Woodland (16%).
- Coastal Foothills Spotted Gum–Ironbark Forest (15%).
- Coastal Plains Smooth-barked Apple Woodland (13%).
In all five principal communities, M. flexuosa contributes 3–5% of total species diversity and ranks in the top ten most important diagnostic species — it is not a rare understorey curiosity but a structurally significant component of the Hunter Valley’s fire-adapted woodland.
Climate in the Hunter Region:
| Parameter | Hunter Region |
|---|---|
| Climate type | Warm temperate, maritime influence near coast |
| Summers | Warm to hot, wet |
| Winters | Cool to cold, dry |
| Annual rainfall range | 677 mm (Singleton) to 1,122 mm (Newcastle) |
| Frost | Regular inland (Cessnock: 28 frost days/year) |
The wide rainfall range (<700 to 1,400 mm/yr across database records) suggests either that the species is broadly tolerant of different soil moisture conditions, or that its current distribution may reflect a past climatic regime.
Conservation
The conservation story of Macrozamia flexuosa is a case study in how poor data can distort threat assessments:
IUCN Red List (Hill 2010): Endangered (EN) — based on an estimated 2,500–10,000 mature individuals and “ongoing decline estimated to exceed 50% over three generations.” Bell (2015, 2019) noted that there is “little indication how that classification was determined.”
Bell (2015, 2019) reassessment: using comprehensive spatial analysis of 588 records across the Hunter Region, Bell determined an estimated population of 1.74 million to 43.5 million individuals, conserved in at least 14 reserves (including the very large populations at Werakata and Columbey National Parks). He recommended a revised IUCN code of Near Threatened (NT) and a conservation risk code of 3RCa (distributional range >100 km; rare but not immediately threatened; adequately conserved).
Residual concerns: despite the large population estimate, Bell noted that M. flexuosa “may currently be in slow decline due to as yet unknown limitations in flowering, pollination and/or dispersal mechanisms over a long period of time (many decades), with the longevity of individual specimens confounding any observable trends.” The critical gap: nobody has studied pollinator identity, pollination success, seed predation, or recruitment in this species. A population of millions of long-lived adults could still be in terminal decline if no seedlings are replacing them.
Threats:
- Habitat loss: the Lower Hunter Spotted Gum–Ironbark Forest — the species’ primary habitat — has lost ~60% of its pre-European extent to clearing, mining, vineyards, and residential expansion. The Cessnock–Hunter Valley area faces intense development pressure.
- Fire: as with all Macrozamia, adults resprout after fire but seedlings and seeds are killed. Masting follows fire, but the interaction between fire frequency and recruitment is unstudied.
- Collecting: historically a threat, though the species’ abundance in reserves reduces this pressure.
Cultivation
| Hardiness | −3 to −5 °C (27 to 23 °F) / USDA zone 9b (zone 9a with protection) |
| Light | Partial shade to full sun |
| Soil | Well-drained; siliceous, sandy to loamy |
| Watering | Moderate; tolerant of a range of soil moisture conditions |
| Adult size | Compact: 45–100 cm fronds, 1–6 leaves |
| Growth rate | Very slow |
| Difficulty | 3/5 |
Macrozamia flexuosa is a small, ornamental cycad that combines the architectural interest of twisted leaves with a glossy, bright green colouration unusual in the genus.
Cold hardiness: the Hunter Region experiences regular frosts inland (28 days/year at Cessnock, minima to −0.4 °C weekly in July), which gives M. flexuosa more frost tolerance than its Queensland relative M. pauli-guilielmi. Applying the standard half-zone safety margin: USDA zone 9b is the safe outdoor planting zone; zone 9a is achievable with winter protection (horticultural fleece, canopy shelter, dry root zone, 15–20 cm mulch). In the northern Mediterranean (French Riviera, Var), sheltered positions with good drainage may succeed, but European cold events (February 1956, January 1985, January 2012) remain a risk. The subterranean caudex provides insulation, and foliage loss is survivable if the growing point is protected.
Light: partial shade to full sun. In habitat, it grows under open eucalypt canopy — the Spotted Gum–Ironbark Forest provides dappled to filtered light.
Soil: well-drained, siliceous — the species grows principally on Permian coal measures and sandstone-derived soils. Avoid heavy clay and waterlogging.
Watering: moderate. The rainfall range in the native habitat (677–1,122 mm) is summer-dominant. The species appears broadly tolerant of soil moisture variation.
Container culture: the very compact size (1–6 leaves, caudex 8–20 cm diameter) and slow growth make it an excellent container specimen. The twisted, glossy fronds are more decorative than the dull-green straight fronds of section Macrozamia species. For European growers, this is primarily a container or conservatory plant — to be brought under cover during cold snaps.
Buying Advice
Availability: Macrozamia flexuosa is very rare in cultivation outside Australia. Specialist Australian cycad nurseries occasionally offer seeds or small plants. The IUCN Endangered listing (even if debated) means that export regulations may apply. Be aware of the hybridisation zones: plants from the Cessnock area may be hybrids with M. reducta (intermediate characters: partially twisted rachis, some basal spines). Ask for provenance data and examine the basal pinnae — pure M. flexuosa should have no basal spines.
Propagation
Seed: the only method. Clean the red sarcotesta (gloves — toxic). Sow in well-drained sandy mix at 22–28 °C. Delayed fertilisation: seeds not ready to germinate for approximately 12 months after ripening. Growth is very slow.
Pests and Diseases
Scale insects: occasional. Manageable with horticultural oil.
Root rot: in heavy, poorly drained soils.
Toxicity: all parts are toxic. Contains cycasin and macrozamin.
Landscape Use
Macrozamia flexuosa is a collector’s cycad of quiet elegance. Where M. pauli-guilielmi is spectacular (ten twists per metre, pineapple cones), M. flexuosa is subtly ornamental — the bright glossy green pinnae with involute margins catching light differently from the dull-green species that dominate Australian cycad collections. The sparse crown (1–6 leaves) means it is best displayed as a single-specimen container plant where the individual frond structure can be appreciated. Pair it with Macrozamia reducta — the straight-leaved section Macrozamia species with which it shares the Cessnock landscape — to illustrate the contrast between the two sections in a single display. For conservation-minded growers, cultivating this species ex situ contributes to genetic insurance for a cycad whose recruitment dynamics remain unknown.
Frequently Asked Questions
Is Macrozamia flexuosa really Endangered?
The current IUCN Red List assessment (Hill 2010) lists it as Endangered, based on limited data. Bell’s comprehensive studies (2015, 2019) found populations potentially numbering in the millions, conserved in at least 14 reserves, and recommended downgrading to Near Threatened. The species may still be in slow, cryptic decline due to limitations in pollination and recruitment — but it is not rare in the field.
How does it differ from Macrozamia pauli-guilielmi?
Longer, more terete (rounded) petioles; broader, brighter green, glossier pinnae with involute margins. M. pauli-guilielmi has shorter, flattened petioles and very narrow (2–4 mm), dull, pale green pinnae that are yellowish beneath.
Can I grow it outdoors in Europe?
In the mildest Mediterranean areas (USDA zone 9b+), possibly — in a sheltered, well-drained position with winter protection. For most European climates, it is a container/conservatory plant. It is hardier than M. pauli-guilielmi but less hardy than M. reducta or M. communis.
Authority Websites and Databases
PlantNET — New South Wales Flora Online
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/…
Stem subterranean, 8–20 cm diam. Leaves 1–6, 45–100 cm, rachis strongly spirally twisted. Pinnae 80–150, bright green, glossy, discolorous, involute margins. Male cones 15 × 4.5 cm. Female cones 10–16 × 7–11 cm. Seeds 2.4–2.7 × 1.9–2.3 cm, red. Bulahdelah to Lake Macquarie on siliceous soils. Hybridises with M. communis on the NC.
POWO — Plants of the World Online (Kew)
https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:977867-1
Accepted species. First published by C. Moore.
IUCN Red List
https://www.iucnredlist.org/species/41963/10601899
Endangered (EN) — Hill 2010. Based on estimated decline exceeding 50% over three generations. Note: Bell (2015, 2019) recommends Near Threatened based on comprehensive field data.
Bell, S.A.J. (2019) — Cunninghamia
Comprehensive review of distribution, habitat and conservation status. EOO 6,319 km², AOO 696 km², estimated population 1.74–43.5 million. Recommends NT. Conserved in at least 14 reserves. May be in slow decline from unknown pollination/dispersal limitations.
Bibliography
Bell, S. A. J. (2004). Vegetation of Werakata National Park, Hunter Valley, New South Wales. Cunninghamia, 8(3), 331–347.
Bell, S. A. J. (2015). Distribution, habitat and conservation status of Macrozamia flexuosa (Zamiaceae) in Lake Macquarie LGA and the lower Hunter Valley of New South Wales. Proceedings of the Linnean Society of New South Wales, 137, 1–22.
Bell, S. A. J. (2019). Macrozamia flexuosa C. Moore (Zamiaceae): a review of distribution, habitat and conservation status of an endemic cycad from the Hunter Region of New South Wales. Cunninghamia, 19, 1–24.
Habib, S., Dang, V.-C., Ickert-Bond, S. M., Zhang, D., Siniscalchi, C. M., & Stevenson, D. W. (2022). Phylotranscriptomics reveal the spatio-temporal distribution and morphological evolution of Macrozamia. Frontiers in Plant Science, 13, 1005303.
Hill, K. D. (1998). Cycadophyta. Flora of Australia, 48, 597–661.
Hill, K. D. (2010). Macrozamia flexuosa. The IUCN Red List of Threatened Species.
Jones, D. L. (2002). Cycads of the World (2nd ed.). New Holland Publishers, Sydney.
Moore, C. (1883). Macrozamia flexuosa. Original description.