Macrozamia serpentina

Macrozamia serpentina is a cycad with no visible trunk from central-eastern Queensland, in eastern Australia, confined to soils derived from serpentinite between Marlborough and Yaamba, north of Rockhampton, where it grows in low eucalypt woodland. This species of the genus Macrozamia, close to Macrozamia miquelii but smaller, carries a sparse crown of 5 to 12 arching, dark green leaves whose lowest leaflets are reduced to spines. First known under the informal name Macrozamia sp. (Marlborough), it was described in 2001 by David Jones and Paul Forster. It is listed as Near Threatened by the IUCN and as Endangered in Queensland.

Key facts about Macrozamia serpentina

  • Accepted name: Macrozamia serpentina D.L.Jones & P.I.Forst. (2001), accepted by The World List of Cycads (version 2026.08.15) and the Australian Plant Census
  • Former names and synonyms: no synonym; informal phrase name before the description: Macrozamia sp. (Marlborough P.I.Forster+ PIF12269A)
  • Family: Zamiaceae, order Cycadales; section Macrozamia
  • Common names: no English common name is attested
  • Natural range: central-eastern Queensland, Australia, between Marlborough and Yaamba, north of Rockhampton (Leichhardt and Port Curtis districts)
  • IUCN status: Near Threatened (NT B1b(iii)), assessment by J.D. Bösenberg dated 14 August 2020 and published in 2022
  • CITES and other protection: CITES Appendix II (annotation #4); Annex B in the European Union; Endangered under Queensland’s Nature Conservation Act 1992; not listed under the federal EPBC Act
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: in the wild, low eucalypt woodland on red clay loams derived from serpentinite, at 80 to 160 m; in cultivation, a free-draining soil
  • Habit and adult size: ovoid underground stem up to 30 cm long and 15 to 25 cm across; 5 to 12 leaves 0.2 to 1 m long
  • In the UK, US and Australia: Royal Botanic Garden Sydney (a plant of wild provenance) and Montgomery Botanical Center (Florida); declared to BGCI by Mackay Regional Botanic Gardens and two other American gardens
  • Toxicity: no data for the species; the genus is very toxic to people and animals (see Toxicity and precautions)

How to recognise Macrozamia serpentina

It is a small relative of Macrozamia miquelii: few arching leaves with a straight axis, widely spaced leaflets, the lowest reduced to stiff spines, and small, slender cones. The original description (Jones, Forster and Sharma, 2001) gives the following measurements.

  • Stem: underground, ovoid, up to 30 cm long and 15 to 25 cm across, unbranched.
  • Leaves: 5 to 12 in a sparse crown, 0.2 to 1 m long, broadly elliptic in outline, obliquely erect then spreading and arching, dark green and semi-glossy, flat in cross-section; young leaves light green; expanded base covered in soft grey wool; petiole 2 to 15 cm long; axis straight, not or slightly twisted.
  • Leaflets: 70 to 100 per leaf, linear, 15 to 45 cm long and 4 to 8 mm wide, thick, dark green and glossy above, slightly paler beneath, with a white callus at the base and a sharp tip; the lowest are gradually reduced to 5 to 8 pairs of stiff spines.
  • Male cones: 1 to 3, cylindrical, 12 to 20 cm long and 2.5 to 3.5 cm across, green.
  • Female cones: 1 or 2, cylindrical to barrel-shaped, 14 to 22 cm long and 6.5 to 8 cm across, green, with terminal spines 0.5 to 2 cm long.
  • Seeds: oblong to ovoid, 1.8 to 2.5 cm long and 1.5 to 2 cm wide, with light orange to red flesh.

Hybrids

No hybrid, natural or garden-raised, has been documented.

Possible confusion

The main confusion is with Macrozamia miquelii, its closest relative according to a partial allozyme analysis (Jones et al., 2001). The original description separates them as follows.

  • Number of leaves: 5 to 12 in Macrozamia serpentina, against 20 to 80 in Macrozamia miquelii.
  • Leaflets: 70 to 100, against 80 to 180.
  • Male cones: 2.5 to 3.5 cm across, against 3.8 to 6.5 cm.
  • Female cones: 14 to 22 cm long and 6.5 to 8 cm across, against 25 to 40 cm and 10 to 15 cm, with shorter terminal spines (1.5 to 2 cm, against 2 to 4.5 cm).

The other species of the same group, such as Macrozamia mountperriensis, Macrozamia longispina and Macrozamia douglasii, live further south. In the 2001 key, Macrozamia serpentina is recognised by its slender male cones (2.5 to 3.5 cm across) and its small male scales (8 to 12 mm by 4 to 8 mm).

Taxonomy

Macrozamia serpentina D.L.Jones & P.I.Forst. is accepted by The World List of Cycads and the Australian Plant Census. It belongs to section Macrozamia, that of the larger species whose lowest leaflets are reduced to spines, and to the Macrozamia miquelii group.

It was described in 2001 in the revision of this group by David Jones, Paul Forster and Ish Sharma, published in the journal Austrobaileya. The authors recognise seven species, all from eastern Queensland: Macrozamia cardiacensis, Macrozamia douglasii, Macrozamia longispina, Macrozamia macleayi, Macrozamia miquelii, Macrozamia mountperriensis and the new Macrozamia serpentina, whose description is signed by Jones and Forster. Before its description the plant was known by the phrase name Macrozamia sp. (Marlborough P.I.Forster+ PIF12269A), used in the census of Queensland plants (Forster, 1997). The name has not changed since.

Etymology and history

The epithet comes from the Latin serpentinus, “growing on serpentine rock” (Jones et al., 2001), and recalls the serpentinite soils of the type locality. The authors note that the species grows there alongside a range of other plants restricted to serpentinite.

The type was collected on 4 November 1992 by Paul Forster and Peter Machin 1 km west of Glen Geddes, in the Port Curtis district (Forster PIF12266; holotype in the Queensland Herbarium, Brisbane, BRI; isotype in Canberra, CANB). The description cites older collections, among them one made in December 1966 between Canoona and Glen Geddes. Nothing is documented about its introduction into cultivation.

Common names

No English common name specific to the species is attested in published sources (The World List of Cycads, Flora of Australia, Species+, Atlas of Living Australia), and no Aboriginal name is recorded. Gardeners and botanists use the scientific name.

In the wild

The species lives in the Leichhardt and Port Curtis districts, between Marlborough and Yaamba, north of Rockhampton (Queensland). According to the Flora of Australia profile, compiled from the original description, it grows at 80 to 160 m in low woodland with a mixed grassy and shrubby understorey, on red clay loams derived from serpentinite; the associated trees include Corymbia xanthope and Eucalyptus fibrosa. The Queensland Government’s WildNet profile adds steep, rocky slopes. The specimens cited come notably from Glen Geddes, Mount Slopeaway, Coorumburra Station and the Marlborough–Glenprairie road.

According to WildNet, citing Jones et al. (2001), the cones shed pollen in October and November and are attended by the thrips Cycadothrips chadwicki, and the seeds ripen between March and May. No other study of the pollination of the species has been published.

Conservation status and regulation

The conservation statuses differ. Macrozamia serpentina is listed as Near Threatened (NT) on the IUCN Red List under criterion B1b(iii), a restricted range with a continuing decline in habitat quality. The assessment, by J.D. Bösenberg, is dated 14 August 2020 and was published in 2022 (The World List of Cycads, GBIF and Crossref, checked on 26 October 2026). In Queensland, on the other hand, it is listed as Endangered under the Nature Conservation Act 1992, as its authors already noted in 2001, a listing confirmed by the Flora of Australia, WildNet and the Atlas of Living Australia; the Atlas shows no listing under the federal Environment Protection and Biodiversity Conservation Act 1999 (EPBC).

In 2001 its authors judged it poorly conserved, with no population in a conservation reserve, and noted that the serpentinite plant communities where it lives are themselves threatened by clearing, mining and agriculture.

Like all Macrozamia, it has been listed in CITES Appendix II since 4 February 1977, with annotation #4 in the version adopted at CoP20, in force since 5 March 2026: live plants need an export permit, while seeds, pollen and seedlings grown in vitro in sterile containers are exempt. In the European Union it falls under Annex B of Regulation (EC) No 338/97, as amended by Regulation (EU) 2026/1383, applicable since 29 June 2026 (Species+, checked on 26 October 2026). Check the regulations in force, and the customs and plant-health rules, before any purchase abroad.

In practice, buy only seed-grown plants of known origin.

Growing Macrozamia serpentina

No source describes the cultivation of this species, and no grower has reported it on the forums: the advice below rests on its habitat and on the general rules for the genus. Nothing suggests that a serpentine soil is needed in cultivation.

Outdoor and in-ground cultivation

  • Soil: free-draining; in the wild, red clay loams, which sets the species apart from the many Macrozamia of sandy soils.
  • Light: in the wild, under a low, open eucalypt canopy; a bright position suits it. Its tolerance of full sun outside Australia is not documented.
  • Climate: the species lives at low altitude in subtropical Queensland; no data exist on its resistance to cold (see Cold hardiness).
  • Growth: no data for the species.

Container cultivation

No container culture has been described. A deep pot suits the underground stem; use a free-draining mix and keep the plant frost-free in winter, since its tolerance of cold is unknown.

In cultivation in the UK, US and Australia

  • Australia: the Royal Botanic Garden Sydney lists one accession of wild provenance numbered in 2021 (S2021-0670), according to its Garden Explorer. Mackay Regional Botanic Gardens (Queensland) also declares the species to BGCI.
  • United States: Montgomery Botanical Center (Coral Gables, Florida) lists accessions numbered in 2003 (20030070) and 2022 (20220003) in its online catalogue; Naples Botanical Garden (Florida) and Moore Farms Botanical Garden (Lake City, South Carolina) declare it to BGCI. A BGCI declaration says that a garden has held the plant, not that a living specimen is there today.
  • United Kingdom: no garden declares the species to BGCI (checked on 26 October 2026).

No grower in the English-speaking world has published a cultivation result.

Propagation

Propagation is by seed. Plants are male or female: both sexes are needed and, in cultivation, hand-pollination is required to obtain fertile seed. No germination data specific to the species have been published.

Pests and diseases

No problem specific to the species is documented. For Macrozamia grown in Europe, growers’ forums mainly mention scale insects and rot in cold, wet soil (see the genus page).

Cold hardiness

There are no data: neither cultivation reports nor published climate records for its habitat. Its hardiness is unknown.

Mediterranean and European experience

No cultivation of the species has been reported in Europe. On the French Fous de palmiers forum, in March 2014, a grower reported the opinion of an Australian nurseryman specialising in cycads, who placed Macrozamia serpentina in his last group, that of the “not very hardy” species of the Queensland coast, without giving temperatures. It is an opinion, not a trial.

United Kingdom, United States and Australia

No dated report exists on the English-language forums that can be read. For the region only, the Bureau of Meteorology’s Rockhampton Aero station, on the coastal plain at 10 m, records frost on fewer than one day a year on average and a lowest temperature of −1.0 °C (30.2 °F), on 23 June 1949; the habitat lies further north and slightly higher, and no station measures it directly. Any hardiness figure would be a guess. Outside frost-free climates, grow it in a pot that can be brought under glass in winter.

Toxicity and precautions

No toxicity data specific to Macrozamia serpentina have been published, but the risk is well documented for the genus, including its close relative Macrozamia miquelii, and the plant should be treated as very toxic, especially its seeds and young leaves. Macrozamia contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, a powerful poison of the liver; cattle that eat the young leaves can develop a locomotor disorder of the hindquarters, the “zamia staggers”, which McKenzie (2006) describes as irreversible, with no treatment (see the genus page).

Wear gloves to handle the seeds, keep them out of reach of children, dogs and livestock, and contact a poison centre, a doctor or a vet without delay in case of ingestion.

Traditional uses

No use specific to Macrozamia serpentina is documented. Asmussen’s (2011) review of the eating of Macrozamia seeds by Aboriginal peoples does not mention this species (see the genus page).

Frequently asked questions

Why is it called serpentina?

Because of its soil. The epithet means “growing on serpentine”: the species lives on soils derived from serpentinite, a rock that carries a distinctive flora in the Marlborough area.

How does it differ from Macrozamia miquelii?

By its size. Macrozamia serpentina has only 5 to 12 leaves and 70 to 100 leaflets per leaf, and its cones are smaller and more slender, with shorter spines.

Is it endangered?

It depends on the list. The IUCN lists it as Near Threatened (assessment published in 2022), but Queensland lists it as Endangered. In 2001 no population was protected in a reserve.

How hardy is it?

Nobody knows. No cultivation report and no climate data for its habitat exist; an Australian nurseryman, quoted on a French forum, ranks it among the least hardy Macrozamia, without figures.

Does it need serpentine soil in cultivation?

Nothing suggests so. No source describes its cultivation; a free-draining soil remains the basic rule for Macrozamia.

Is it poisonous?

Probably, like all Macrozamia. No analysis specific to the species exists, but the seeds and young leaves of the genus are very toxic to people, pets and livestock.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Jones, D.L., Forster, P.I. & Sharma, I.K. (2001). Revision of the Macrozamia miquelii (F.Muell.) A.DC. (Zamiaceae section Macrozamia) group. Austrobaileya 6(1): 67–94 (pp. 90–92, figs 19–21, for this species). doi:10.5962/p.299651 [Original description, type, comparison with Macrozamia miquelii, status, etymology; full text (PDF made available by The World List of Cycads).]
  • Forster, P.I. (1997). Spermatophyta – Gymnospermae. In: Henderson, R.J.F. (ed.), Queensland Plants: Names & Distribution: 211–212. Department of Environment, Indooroopilly. [Phrase name Macrozamia sp. (Marlborough); cited by Jones et al. (2001).]
  • Batianoff, G.N., Reeves, R.D. & Specht, R.L. (1991). The serpentinite flora of the humid subtropics of eastern Australia. Proceedings of the Royal Society of Queensland 101: 137–157. [Serpentinite flora; cited by Jones et al. (2001).]
  • Bösenberg, J.D. (2022). Macrozamia serpentina. The IUCN Red List of Threatened Species 2022: e.T178872A50525981. doi:10.2305/IUCN.UK.2022-1.RLTS.T178872A50525981.en [Near Threatened, criterion B1b(iii); assessment dated 14 August 2020, from Crossref.]
  • Asmussen, B. (2011). “There is likewise a nut…” a comparative ethnobotany of Aboriginal processing methods and consumption of Australian Bowenia, Cycas, Macrozamia and Lepidozamia species. Technical Reports of the Australian Museum, Online 23(10): 147–163. doi:10.3853/j.1835-4211.23.2011.1575 [Aboriginal uses; the species is not mentioned.]
  • McKenzie, R.A. (2006). Toxicology for Australian Veterinarians: cycads (Cycas, Macrozamia, Lepidozamia, Bowenia), pp. 282–288. Animal Health Australia, Australian Animal Pathology Standards Program (PDF): https://aapspextranet.animalhealthaustralia.com.au/wp-content/uploads/2019/04/tav7_17_unknowntoxins_pt2.pdf [Australian veterinary reference text; describes the cattle syndrome as irreversible, ending in paralysis of the hindquarters, with no treatment.]
  • Calonje, M., Stevenson, D.W. & Osborne, R. (2026). The World List of Cycads, version 2026.08.15. Montgomery Botanical Center, Coral Gables. doi:10.5281/zenodo.21958524 [Reference list.]