Cycas conferta

Cycas conferta is a cycad with sea-green foliage and crowded, overlapping leaflets that forms small, isolated stands on granite and sandstone in the Pine Creek area and Kakadu National Park, in Australia’s Northern Territory. This species of the genus Cycas was described in 1993 by Sharon Chirgwin and David Wigston, of the Northern Territory University; growers knew it earlier as Cycas sp. ‘Pine Creek’. Its name, from the Latin confertus, “crowded”, refers to the leaflets packed along the leaf axis. The IUCN lists it as Vulnerable.

Key facts about Cycas conferta

  • Accepted name: Cycas conferta Chirgwin (1993), according to The World List of Cycads; Species+ writes Cycas conferta Chirgwin ex Chirgwin & Wigston; POWO could not be consulted directly
  • Former names and synonyms: earlier horticultural name Cycas sp. ‘Pine Creek’; treated as a synonym of Cycas lane-poolei by de Laubenfels and Adema (1998), a view not followed
  • Family: Cycadaceae, order Cycadales
  • Common names: no English or Aboriginal name could be verified
  • Natural range: Australia, Northern Territory, from Kakadu National Park (Twin Falls, Goodparla) to west of Pine Creek
  • IUCN status: Vulnerable (VU), reassessment by N. S. Nagalingum (Red List version 2023-1), VU according to GBIF; the Flora of Australia indicates Near Threatened (NT, 2022) (see Conservation status)
  • CITES and other protection: CITES Appendix II (seeds exempt under annotation #4); Annex B in the European Union
  • Documented hardiness: no data; a tropical species to be kept frost-free (see Cold hardiness)
  • Light and soil: in the wild, open savanna woodland on sandy soils over granite or coarse sandstone, rocky outcrops near creeks
  • Habit and adult size: trunk to 4 m, rarely 7 m, 9 to 13 cm across; leaves 60 to 110 cm long
  • In the UK, US and Australia: Montgomery Botanical Center (Florida) and UC Botanical Garden at Berkeley (California); photographed at the George Brown Darwin Botanic Gardens (2016); no British record
  • Toxicity: not studied for the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas conferta

Look for dull, pale green, slightly bluish leaves; short, broad leaflets so crowded that they overlap, the same colour on both faces; and a long petiole that usually has no spines. Ken Hill’s revision (1996), which completes the original description, and the Flora of Australia give the following characters:

  • Trunk: up to 4 m, rarely 7 m, 9 to 13 cm across.
  • Leaves: 70 to 110 cm long, flat or slightly keeled, with 160 to 240 leaflets, always ending in a spine that is sometimes toothed; petiole 20 to 45 cm, with loose white down, usually unarmed.
  • Leaflets: 70 to 120 mm by 6 to 8 mm, hairless, blue-green when young then mid-green, dull to semi-glossy, almost the same colour on both faces, flat, 5 to 8 mm apart and often overlapping; midrib raised equally above and below; a few stomata sometimes on the upper face.
  • New growth: dense white down with some orange hairs; cataphylls (the scales protecting the growing point) 6 to 9 cm, with dense orange down.
  • Male cones: orange-brown, ovoid, 11 to 18 cm by 8 to 12 cm.
  • Megasporophylls (the fertile leaves of female plants): 17 to 22 cm long, with grey and orange down, bearing 2 to 4 ovules; sterile tip narrowly triangular, 45 to 75 mm, regularly toothed.
  • Seeds: narrowly ovoid, green then orange, with a bloom, about 40 mm by 30 mm; collectors’ labels describe ripe seeds as brown or plum-coloured.

The original description by Chirgwin and Wigston (1993) differs on several points: it describes a shrub no taller than 3.5 m, “sea-green” leaves 60 to 105 cm long, leaflets 3 to 8.5 mm wide with a groove along the midrib, a megasporophyll tip with poorly developed teeth or none, and pear-shaped ovules with a marked point, purplish brown when ripe. It also stresses the presence of stomata on both faces of the leaflets, a rare character among the Northern Territory Cycas. De Laubenfels and Adema (1998) thought this variability might betray a mixture of taxa in the 1993 description.

Hybrids

Hill (1996) reports apparent natural hybrids with Cycas calcicola. The populations of Mount Bundey and Hayes Creek are intermediate between Cycas conferta and Cycas armstrongii, and those of Goodparla show a slight influence of the latter; the Flora of Australia notes intergradation with Cycas armstrongii where the ranges meet. No garden hybrid is documented.

Possible confusion

The most frequent confusion is with Cycas armstrongii. According to Hill (1996), that species has shorter petioles, more often spiny, and glossy leaflets, paler beneath and more widely spaced; it is also smaller. Hill found the petioles entirely spineless in about 90% of plants of Cycas conferta, against 10 to 15% in Cycas armstrongii. Cycas papuana, from western Papua New Guinea, shares the long petioles and crowded leaflets but has sturdier male cones. Cycas canalis, further west, has much longer leaflets (100 to 205 mm) that do not overlap.

Taxonomy

Cycas conferta is accepted by The World List of Cycads; POWO could not be consulted directly. S. K. Chirgwin and D. Wigston published it in 1993 in “A new species of Cycas from the Northern Territory”, Journal of the Adelaide Botanic Gardens 15(2): 147–148, with Chirgwin as sole author of the name; Species+ writes the authority “Chirgwin ex Chirgwin & Wigston”. The type is a female plant collected by George Brown on 21 April 1987 at Harriet Creek, east of Pine Creek, on Kombolgie sandstone and yellow clay according to the label; the holotype is in Darwin (DNA D0029214), with an isotype there and another in Sydney.

Ken Hill (1996) placed it in series Armstrongianosae (section Cycas, subsection Endemicae), with Cycas armstrongii, Cycas canalis, Cycas orientis, Cycas lane-poolei and Cycas xipholepis, species with flat leaflets, no protective layer beneath the epidermis and a very thin cuticle. De Laubenfels and Adema (1998) sank it, with Cycas canalis, into the synonymy of Cycas lane-poolei, from Western Australia; The World List of Cycads does not follow this view.

Etymology and history

The epithet comes from the Latin confertus, “crowded, pressed together”, and refers to the leaflets packed along the leaf axis (Chirgwin and Wigston 1993; Haynes 2022). The authors recalled that local botanists had recognised the plant as distinct several years before its description, which continued the revision of the Northern Territory Cycas begun by J. R. Maconochie, who died in an accident before completing it. Before 1993 it appeared in horticultural works as Cycas sp. ‘Pine Creek’ (de Laubenfels and Adema 1998; PACSOA).

Common names

No English common name could be verified, nor any Aboriginal name. The only other name in use is the horticultural ‘Pine Creek’. The Palm and Cycad Society of Australia quotes Sharon Chirgwin on the beauty of its “sea-green” fronds.

In the wild

Cycas conferta is endemic to the Northern Territory. According to Hill (1996) and the Flora of Australia, it grows mainly on sandy soils over granite or coarse sandstone, in isolated, usually small but dense stands, from Kakadu National Park (near Twin Falls and Goodparla homestead) to west of Pine Creek. Chirgwin and Wigston (1993) describe small groups around the creeks of the Pine Creek area, isolated from other Cycas.

Herbarium labels published through GBIF fill in the picture. At Harriet Creek, the type locality, collectors recorded a very localised, abundant cycad 1.5 to 2 m tall with bluish leaves in open savanna shrubland on shallow gritty soil over coarse granite (1991), and plants up to 1.7 m among granite boulders, whose seeds turn from green and orange to plum brown (2001); a 1991 label estimates the population there at fewer than 250 plants. Other labels describe a stand of only about 50 plants 19 km east of Pine Creek, in open savanna forest of Eucalyptus miniata on deep sandy loam over granite (1991); plants to 4 m, occasionally 7 m, on a stony sandstone slope along the old Goodparla track (1991); about ten plants on a sandy river levee near the South Alligator River crossing (1991); and, in 2024, female plants to 3 m in open Eucalyptus tectifica woodland on a low dolomitic hill above Gunlom Falls. Several labels mention recent fires, and a collector noted weevils on a male cone at Harriet Creek in 2001.

A field note reproduced by the Palm and Cycad Society of Australia (PACSOA) places it north-east of Pine Creek, on wooded hillsides and granite outcrops, under about 1,000 mm of rain a year, with trunks averaging 1.25 m and up to 4.30 m, some branched or suckering, and 40 to 60 leaves in the crown.

Conservation status and regulation

Cycas conferta is listed as Vulnerable (VU) by the IUCN: a reassessment by N. S. Nagalingum was published in Red List version 2023-1 (reference checked on Crossref), and the IUCN data relayed by GBIF give it the VU category (consulted on 21 October 2026). The World List of Cycads shows the same category, with criteria B1ab(i,ii,iv,v), citing the earlier assessment by H. Ottley (2010). The Flora of Australia, whose profile was updated in December 2025, states instead “Listed as Near Threatened, 2022”; the sources consulted do not explain this difference, and the Red List itself could not be consulted.

The authors of the species estimated the total population in 1993 at 200 to 300 plants, threatened by mining, road building and collectors. Hill (1996) described small, localised populations threatened by collectors, whose regeneration suffers from too frequent fires and, to a lesser extent, from seed collecting, although some stands are protected in Kakadu National Park.

Like every species in the genus except Cycas beddomei, Cycas conferta is listed in CITES Appendix II, through the listing of the family Cycadaceae, included since 4 February 1977. The listing carries annotation #4 (CoP20 version, in force since 5 March 2026): seeds, pollen, seedlings or tissue cultures obtained in vitro and transported in sterile containers, and cut flowers of artificially propagated plants, are not subject to CITES, whereas international trade in the plants themselves requires an export permit. Australia, the United Kingdom and the United States apply CITES through their own national legislation; in the European Union the species is in Annex B of Regulation (EC) No 338/97, whose annexes in force are set by Commission Regulation (EU) 2026/1383, applicable since 29 June 2026. Species+, the official CITES database, names the species and confirms this status. This general information does not replace the official texts: check the rules in force before buying or exchanging plants, and ask for proof that the plant was raised in cultivation.

Growing Cycas conferta

In short: no published growing account exists for the species itself. It thrives in hot, humid tropical gardens such as Nong Nooch in Thailand, and a French specialist nurseryman ranks the Northern Territory Cycas among the hardest to grow in Europe.

Outdoor and in-ground cultivation

The Palm and Cycad Society of Australia calls it “a horticulturalist’s dream” for its soft, sea-green foliage, without giving growing advice. In a 2021 note on growing Australian Cycas in a European climate, the French nurseryman Simon Lavaud (Cycadales.eu) illustrates “a magnificent specimen” of Cycas conferta photographed in 2019 at the Nong Nooch Tropical Botanical Garden, in Thailand, where, he writes, the Australian Cycas, including those of the Northern Territory, thrive in an almost constant 25 to 30 °C (77 to 86 °F) with a short dry season. In Australia, a member of the French forum Fous de palmiers photographed plants at the George Brown Darwin Botanic Gardens in 2016. Its habitat (sandy soils over granite, open woodland, a tropical climate with a long dry season) points to full sun and a very free-draining mineral soil; this is a deduction, not a trial result.

Container cultivation

In the United Kingdom and other temperate regions, it is a plant for a heated glasshouse. In his 2021 note, Simon Lavaud classes all the Northern Territory species except Cycas angulata as “very difficult”; Cycas conferta falls into that group by its origin. His general advice for the Australian Cycas is a very mineral substrate, full sun, a glasshouse to lengthen the growing season, and generous watering in hot weather, reduced below 20 °C (68 °F) and stopped when nights fall below 10 °C (50 °F), because of the risk of root rot. These are a grower’s recommendations for the group, not results for this species. A grower in Ravenna, Italy, mentioned it on the Italian forum Tropicamente in 2012 among the Australian blue cycads he found tempting, while fearing the humidity of his region; he reported no growing result. The Jardin zoologique tropical at La Londe-les-Maures, in the south of France, has published no observation on the species.

In cultivation in the UK, US and Australia

  • United States: the online catalogue of Montgomery Botanical Center (Coral Gables, Florida) lists two accessions whose numbers date from 1997; the UC Botanical Garden at Berkeley (California) declares one accession in BGCI PlantSearch, without saying whether the plant grows outdoors or under glass.
  • Australia: plants photographed in 2016 at the George Brown Darwin Botanic Gardens (forum Fous de palmiers). The species does not appear in the Garden Explorer of the Royal Botanic Garden Sydney or of the Australian Botanic Garden Mount Annan.
  • United Kingdom: no record in BGCI PlantSearch or in the British garden catalogues consulted.

Outside these countries, BGCI lists the Fairy Lake Botanical Garden in Shenzhen (China), and Simon Lavaud photographed the species at Nong Nooch. No report from a private grower in the UK, US or Australia could be read; PalmTalk and Dave’s Garden could not be consulted.

Propagation

Like all Cycas, Cycas conferta is dioecious and is raised from seed: a male and a female plant are needed for fertile seed. Some wild plants also branch or produce suckers, according to the field note reproduced by PACSOA, but no published account of germination or of rooting suckers has been found. Seeds are exempt from CITES under annotation #4; ask for seed from cultivated plants.

Pests and diseases

No pest or disease specific to the species is documented. In the wild, too frequent fires harm its regeneration (Hill 1996). In cultivation, scale insects, including Aulacaspis yasumatsui, can attack any Cycas, and root rot in a cold, wet substrate is the cause of failure most often cited for Australian Cycas in Europe (Lavaud 2021).

Cold hardiness

No cold-tolerance value has been published for Cycas conferta, and no dated outdoor growing report outside the tropics has been found. Its range, in the tropical north of the Northern Territory, does not suggest any tolerance of frost, and Simon Lavaud (2021) sees the complete absence of cold as one of the keys to growing the Australian Cycas well.

European experience

No growing result has been published in Europe, in the open ground or in a pot. On the French forum Fous de palmiers, the species appears only in photographs taken in Darwin, and on Tropicamente only as a wish. In the absence of data, grow it under glass, frost-free.

United Kingdom, United States and Australia

No cold reading and no growing report were found. The documented plantings are in tropical or near-tropical settings (Darwin, South Florida) or of unknown placement (Berkeley). No USDA zone can be given without a documented trial.

Toxicity and precautions

No toxicity analysis specific to Cycas conferta has been found. The risk is, however, well documented in the genus: Cycas tissues, and the seeds above all, contain cycasin, which is converted during digestion into methylazoxymethanol, toxic to the liver and nervous system, along with a neurotoxic amino acid, BMAA. North Carolina State University notes that cycasin is present in all parts of the plant, and the ASPCA lists the sago palm (Cycas revoluta) as poisonous to dogs, cats and horses, with vomiting, sometimes bloody diarrhoea, jaundice and liver damage that can be fatal. Until proven otherwise, treat the plant as poisonous: wear gloves to handle the seeds and their fleshy coat, pick up fallen seeds, and keep plants and seeds out of reach of children and pets. If any part is swallowed, contact a poison centre, a doctor or a vet straight away.

Traditional uses

No traditional use specific to Cycas conferta has been found in the sources consulted.

Frequently asked questions

What does “conferta” mean?

“Crowded”. The word comes from the Latin confertus and describes the packed, overlapping leaflets along the leaf axis.

How can Cycas conferta be told from Cycas armstrongii?

Mainly by the petiole and the leaflets. Cycas conferta has a long petiole that is almost always spineless and crowded, dull leaflets of the same colour on both faces; Cycas armstrongii has a shorter, often spiny petiole and glossy, more widely spaced leaflets.

Where can it be seen in the wild?

In the Northern Territory of Australia, around Pine Creek and in Kakadu National Park, where some stands are protected, for example near Goodparla and above Gunlom Falls.

Is it endangered?

Yes. The IUCN lists it as Vulnerable, a category confirmed by the 2023 reassessment, although the Flora of Australia gives Near Threatened. Its populations are small and sensitive to fire and collecting.

Is it hard to grow?

Yes, outside the tropics. It thrives at Nong Nooch in Thailand, but a French specialist nurseryman ranks the Northern Territory Cycas as “very difficult” in Europe, mainly because of root rot in cool, wet conditions.

Can it be grown outdoors in the UK?

No. It is a tropical species with no documented cold tolerance; it needs a heated glasshouse.

Is it poisonous?

It must be assumed so. It has not been studied, but all parts of Cycas are poisonous, especially the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Chirgwin, S.K. & Wigston, D. (1993). A new species of Cycas from the Northern Territory. Journal of the Adelaide Botanic Gardens 15(2): 147–148. [Original description: description, range, population size, conservation; full text consulted (archive.org).]
  • Hill, K.D. (1996). A taxonomic revision of the genus Cycas (Cycadaceae) in Australia. Telopea 7(1): 1–64. doi:10.7751/telopea19963040 [Amended description, range, hybrids and intermediates, conservation, series; full text consulted.]
  • de Laubenfels, D.J. & Adema, F. (1998). A taxonomic revision of the genera Cycas and Epicycas gen. nov. (Cycadaceae). Blumea 43: 351–400. [Synonymy with Cycas lane-poolei, page 365; full text consulted.]
  • Ottley, H. (2010). Cycas conferta. The IUCN Red List of Threatened Species 2010: e.T41958A10611773. doi:10.2305/IUCN.UK.2010-3.RLTS.T41958A10611773.en [Earlier assessment, VU, cited by The World List of Cycads; reference checked on Crossref, page not consulted.]
  • Nagalingum, N.S. (2023). Cycas conferta. The IUCN Red List of Threatened Species 2023: e.T41958A67340743. doi:10.2305/IUCN.UK.2023-1.RLTS.T41958A67340743.en [Current assessment; reference checked on Crossref, VU category relayed by GBIF; page not consulted (access blocked).]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. doi:10.11646/phytotaxa.550.1.1 [Etymology of the epithet; cited by The World List of Cycads, text not consulted.]
  • 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 checklist: accepted name, original publication, type, range, synonyms, IUCN status; consulted directly.]