Macrozamia viridis

Macrozamia viridis is a small cycad with no visible trunk from a very small area of southern Queensland, in eastern Australia: the Girraween and Wyberba district, on the Darling Downs near the New South Wales border, where it grows on deep granite sands in open eucalypt forest dotted with large granite outcrops. This species of the genus Macrozamia owes its name to its bright green, glossy leaflets, carried on short leaves whose axis is spirally twisted. First collected in 1933, it was described only in 1994, by David Jones and Paul Forster. It is listed as Endangered by the IUCN and in Queensland.

Key facts about Macrozamia viridis

  • Accepted name: Macrozamia viridis D.L.Jones & P.I.Forst. (1994), accepted by The World List of Cycads (version 2026.08.15) and the Australian Plant Census
  • Former names and synonyms: no synonym; before its description, known by the informal phrase name Macrozamia sp. (Wyberba S.T.Blake 4646)
  • Family: Zamiaceae, order Cycadales; section Parazamia
  • Common names: no English common name is attested
  • Natural range: southern Queensland, Australia, Girraween and Wyberba district (Darling Downs)
  • IUCN status: Endangered (EN B1ab(iii,v)+2ab(iii,v)), assessment by J.D. Bösenberg dated 21 August 2020 and published in 2022
  • CITES and other protection: CITES Appendix II (annotation #4); Annex B in the European Union; Endangered in Queensland (Nature Conservation (Plants) Regulation 2020); not listed under the federal EPBC Act
  • Documented hardiness: no cultivation data; nearest weather stations, at about 870 to 880 m, have recorded −5.6 °C (21.9 °F) and −8.4 °C (16.9 °F) (see Cold hardiness)
  • Light and soil: in the wild, moderately wet open eucalypt forest on deep granite sands; in cultivation, a very free-draining soil
  • Habit and adult size: underground stem 10 to 20 cm across, sometimes branching into a clump; 1 to 8 leaves 35 to 60 cm long
  • In the UK, US and Australia: no garden in these three countries declares the species to BGCI or lists it in the online catalogues checked
  • Toxicity: no data for the species; the genus is very toxic to people and animals (see Toxicity and precautions)

How to recognise Macrozamia viridis

It is recognised by its dwarf habit, its short, dark green, glossy leaves whose axis makes one to three spiral turns, and its small cones. The original description (Jones and Forster, 1994) gives the following measurements.

  • Stem: underground, more or less ovoid, 10 to 20 cm across, sometimes branching into a clump of up to six stems.
  • Leaves: 1 to 5 in a sparse crown according to the original description (2 to 8 according to the Flora of Australia), 35 to 60 cm long, dark green and glossy, spreading; expanded base densely covered in soft, fawn wool; petiole 9 to 21 cm long, 8 to 14 mm wide at the lowest leaflet; axis spirally twisted one to three times.
  • Leaflets: 80 to 160 per leaf, broadly linear, 7 to 20 cm long and 3 to 11 mm wide (5 to 11 mm according to the Flora of Australia), dark green and glossy above, green beneath, channelled, set at about 60° to the axis; callus at the base yellowish white to reddish orange.
  • Male cones: more or less cylindrical, 9 to 18 cm long and 3.5 to 5 cm across.
  • Female cones: ovoid, 8 to 14 cm long and 5.5 to 7 cm across, with terminal spines up to about 1.5 cm long.
  • Seeds: ovoid, 20 to 24 mm long and 17 to 23 mm wide according to the Flora of Australia, with orange to red flesh when ripe.

The authors call it “a very distinctive species”, related to Macrozamia plurinervia but dwarf, with much shorter leaves, shiny, bright green leaflets, much smaller cones and smaller seeds. The Flora of Australia rather compares it with Macrozamia fawcettii, from which it differs by the smaller size of all its parts and a more clearly flattened petiole.

Hybrids

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

Possible confusion

The risk of confusion concerns the other small Macrozamia with a spiralled axis from southern Queensland and northern New South Wales.

  • Macrozamia plurinervia: more robust, with leaves 85 to 115 cm long, duller leaflets and glaucous cones.
  • Macrozamia fawcettii: larger in all its parts, with a less flattened petiole (Flora of Australia).
  • Macrozamia cranei, Macrozamia occidua, Macrozamia machinii and Macrozamia conferta: small neighbouring species of the Darling Downs, described in the same paper of 1994; the plant’s origin is often the best clue.

Taxonomy

Macrozamia viridis D.L.Jones & P.I.Forst. is accepted by The World List of Cycads and the Australian Plant Census. It belongs to section Parazamia, that of the small species with an underground stem, without spiny leaflets or mucilage canals, and, according to its authors, to the “Macrozamia plurinervia complex”, which brings together species with fairly broad, shallowly channelled leaflets.

It was described in 1994 by David Jones, of the Australian National Botanic Gardens, and Paul Forster, of the Queensland Herbarium, in a paper in Austrobaileya describing seven new species of section Parazamia from Queensland. The authors explain that these very localised species have diverged in long-isolated populations, and that describing them should help their management and conservation. Before its description, the plant was listed in the census of Queensland plants under the phrase name Macrozamia sp. (Wyberba S.T.Blake 4646) (Forster, 1994). The name has not changed since.

Etymology and history

The epithet comes from the Latin viridis, “green”, in reference to the green leaflets (Jones and Forster, 1994), bright green according to The World List of Cycads.

The plant was first collected in January 1933 by the botanist S.T. Blake at Wyberba. The type is a male plant collected at the same place on 7 January 1993 by Paul Forster and Peter Machin (Forster 12634B; holotype in the Queensland Herbarium, Brisbane, BRI; isotype in Canberra, CBG). The authors thank the staff of Girraween National Park for bringing the species to their attention. Nothing is documented about its introduction into cultivation. The journal of the Cycad Society of South Africa devoted an article to it (Osborne and Forster, 2008).

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 is known only from the Girraween and Wyberba district, in the south of the Darling Downs (Queensland), near the border with New South Wales. According to the original description, it grows on deep granite sands in open eucalypt forest with large granite outcrops and pavements, together with Brachyloma daphnoides, Bossiaea rhombifolia, Stylidium graminifolium, Leucopogon melaleucoides and Persoonia tenuifolia, among others. The Flora of Australia speaks of moderately wet eucalypt woodland and calls it “highly localised and probably rare”.

Cones mature between October and January and seeds ripen in March and April. Thanks to their underground stem, adult plants resprout after a fire has destroyed their leaves, but seedlings and unburied seeds are usually killed by fire (Flora of Australia; WildNet). No study of the pollination of the species has been published.

Conservation status and regulation

Macrozamia viridis is listed as Endangered (EN) on the IUCN Red List under criteria B1ab(iii,v)+2ab(iii,v): its range and area of occupancy are very small, fragmented or limited to few locations, with a continuing decline in habitat quality and in the number of plants. The assessment, by J.D. Bösenberg, is dated 21 August 2020 and was published in 2022 (The World List of Cycads, GBIF and Crossref, checked on 26 October 2026). It is also listed as Endangered in Queensland (Nature Conservation (Plants) Regulation 2020, November 2022 list), according to the Flora of Australia, WildNet and the Atlas of Living Australia; WildNet also records an earlier listing as Rare (1996–2000). The Atlas shows no listing under the federal Environment Protection and Biodiversity Conservation Act 1999 (EPBC). In 1994 its authors knew only two populations, one of them in Girraween National Park.

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: so localised a species cannot bear any collection from the wild.

Growing Macrozamia viridis

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.

Outdoor and in-ground cultivation

  • Soil: very free-draining and sandy, like the deep granite sands of its habitat.
  • Light: in the wild, in open eucalypt forest; a bright position suits it. Its tolerance of full sun outside Australia is not documented.
  • Water: its habitat is described as moderately wet; water during growth, let the soil dry between waterings and avoid cold, waterlogged soil in winter.
  • Growth: no data for the species; small Macrozamia with an underground stem are generally very slow.

Container cultivation

No container culture has been described. Given its small size, its rarity and the lack of cold data, a deep pot with a sandy, very free-draining mix seems the most sensible choice outside its native climate.

In cultivation in the UK, US and Australia

No botanic garden in the United Kingdom, the United States or Australia declares the species to BGCI, and it does not appear in the online catalogues of the Royal Botanic Garden Sydney, the Australian Botanic Garden Mount Annan or Montgomery Botanical Center (checked on 26 October 2026). The only declarations to BGCI come from three gardens in continental Europe. No grower in the English-speaking world has published a cultivation result.

Propagation

Propagation is by seed; in the wild the seeds ripen in March and April. Plants are male or female: both sexes are needed and, in cultivation, hand-pollination is required to obtain fertile seed. Since plants sometimes form clumps of several stems, dividing off a stem is possible in theory, but no source describes it for this species. No germination data 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

No cultivation report exists, and no climate record has been published for the habitat itself. The nearby weather stations only give an idea of the regional climate.

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 viridis among the “less hardy” species of inland Queensland, one step below those of New South Wales, 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. Two nearby stations of the Bureau of Meteorology give an idea of the regional climate. Wallangarra Post Office, at 880 m on the border, recorded about 21 days a year at or below 0 °C (32 °F) in the air and a lowest temperature of −5.6 °C (21.9 °F), on 24 June 1986 (temperatures measured from 1968 to 1992); Applethorpe, at 872 m further north, records about 33 such days a year and a lowest temperature of −8.4 °C (16.9 °F), on 17 July 1970. These figures describe the region, where the plant lives with an underground stem protected by the soil; they say nothing of what a plant in a pot or in wet soil would tolerate. In Britain and in the colder parts of the United States, a pot kept frost-free and dry in winter is the prudent choice.

Toxicity and precautions

No toxicity data specific to Macrozamia viridis have been published, but the risk is well documented for the genus, 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 viridis 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

Where does the name come from?

From the Latin viridis, “green”. It refers to the bright green, glossy leaflets, one of the characters that set it apart from neighbouring species.

Where does it grow?

Only in the Girraween and Wyberba district of southern Queensland, on deep granite sands in open eucalypt forest dotted with granite outcrops.

Is it endangered?

Yes. The IUCN lists it as Endangered (assessment published in 2022), and so does Queensland. In 1994 its authors knew only two populations, one of them in a national park.

How hardy is it?

Nobody knows. No cultivation report exists; the region’s weather stations, at about 870 to 880 m, have recorded −5.6 °C (21.9 °F) and −8.4 °C (16.9 °F). An Australian nurseryman, quoted on a French forum, ranks it among the less hardy Macrozamia, without figures.

How does it differ from Macrozamia plurinervia?

By its size. Macrozamia viridis is dwarf, with leaves 35 to 60 cm long, bright green, glossy leaflets and small cones; Macrozamia plurinervia has leaves 85 to 115 cm long and glaucous cones.

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. (1994). Seven new species of Macrozamia section Parazamia (Miq.) Miq. (Zamiaceae section Parazamia) from Queensland. Austrobaileya 4(2): 269–288 (pp. 281–284, fig. 7, for this species). [Original description, type, habitat, phenology, status, etymology; full text (PDF made available by The World List of Cycads).]
  • Forster, P.I. (1994). Zamiaceae. In: Henderson, R.J.F. (ed.), Queensland Vascular Plants: Names and Distribution: 345. Queensland Department of Environment and Heritage, Brisbane. [Phrase name Macrozamia sp. (Wyberba S.T.Blake 4646); cited by Jones and Forster (1994).]
  • Hill, K.D. (1998). Cycadophyta. In: McCarthy, P.M. (ed.), Flora of Australia 48: 597–661, 717–719. ABRS/CSIRO Publishing, Melbourne. [Description, range, ecology; online version of the flora.]
  • Osborne, R. & Forster, P.I. (2008). Focus on Macrozamia viridis. Encephalartos 95: 11–14. [Reference after The World List of Cycads.]
  • Bösenberg, J.D. (2022). Macrozamia viridis. The IUCN Red List of Threatened Species 2022: e.T41968A50526564. doi:10.2305/IUCN.UK.2022-1.RLTS.T41968A50526564.en [Endangered, criteria B1ab(iii,v)+2ab(iii,v); assessment dated 21 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.]