Cycas couttsiana: the blue cycad of the Gregory Range

Cycas couttsiana is a tree-like cycad with blue-green foliage, endemic to the southern Gregory Range in the interior of northern Queensland, Australia. This species of the genus Cycas was described only in 1992, from plants on Chudleigh Park cattle station, whose owners, Pat and David Coutts, had brought it to the attention of botanists. It differs from the other Australian “blue cycads” in the white down that persists on its young leaves and in its seeds, covered with a bluish bloom. Highly sought after by collectors but slow and prone to rot on its own roots in Europe, it is the species on which grafting onto Cycas revoluta has been tested most extensively. The IUCN lists it as Near Threatened.

Key facts about Cycas couttsiana

Accepted name: Cycas couttsiana K.D.Hill (1992), according to The World List of Cycads; POWO could not be consulted directly
Former names and synonyms: no accepted synonym; treated as a synonym of Cycas angulata by de Laubenfels and Adema (1998), a view not followed; old horticultural name Cycas sp. ‘Glen Idle Blue’
Family: Cycadaceae, order Cycadales
Common names: no English or Aboriginal name verified; garden label “Glen Idle Blue Sago” at the Royal Botanic Garden Sydney
Natural range: Australia, Queensland, southern Gregory Range (upper Stawell River)
IUCN status: Near Threatened (NT), reassessment by J. D. Bösenberg (Red List version 2023-1), NT according to GBIF; Vulnerable under Queensland’s Nature Conservation (Plants) Regulation 2020 (Flora of Australia)
CITES and other protection: CITES Appendix II (seeds exempt under annotation #4); Annex B in the European Union
Documented hardiness: no measured value; to be kept frost-free (see Cold hardiness)
Light and soil: full sun; in the wild, open grassy woodland on red sandy loams derived from basalt or dolerite, at about 750 to 900 m according to herbarium labels
Habit and adult size: trunk to 3 m, rarely 7 m (to 8 m on a herbarium label), 14 to 20 cm across; leaves 100 to 130 cm long
In the UK, US and Australia: Royal Botanic Garden Sydney and Australian National Botanic Gardens (Canberra); Montgomery Botanical Center, Marie Selby Botanical Gardens and Naples Botanical Garden (Florida); no British record
Toxicity: not studied for the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas couttsiana

Three characters together identify it: leaflets fairly broad for a blue cycad, dull blue-green, angled upwards on either side of a strongly keeled leaf; a grey-white down that lingers on the new growth and the underside of the leaflets; and heavily bloomed seeds. The original description by Ken Hill (1992), taken up by the Flora of Australia, gives:

Trunk: up to 3 m tall, rarely 7 m, 14 to 20 cm across.
Leaves: 100 to 130 cm long, strongly keeled (opposite leaflets at an angle of 30 to 90°, sometimes up to 150°), with 180 to 270 leaflets; axis usually ending in a spine; petiole 17 to 21 cm, often covered in grey down.
Leaflets: 170 to 210 mm by 4.5 to 6 mm, hairless above, often finely white-downy beneath, dull blue-green, with recurved margins.
New growth: dense grey-white down mixed with a few pale orange-brown hairs, which persists; cataphylls (the scales protecting the growing point) slender, with pale grey-brown down.
Male cones: ovoid, 15 to 20 cm by 7 to 9 cm, orange-brown.
Megasporophylls (the fertile leaves of female plants): 16 to 26 cm long, with grey down, bearing 4 to 6 ovules; blade narrowly triangular, 40 to 60 mm by 20 to 30 mm, regularly toothed.
Seeds: ovoid, green then yellowish brown, heavily bloomed, 35 to 46 mm long.

In his key, Paul Forster (2001) gives median leaflets 6 to 7.5 mm wide, slightly more than the 1992 description, and notes that the blue colour of the species is intermediate: less intense and less lasting than in Cycas cairnsiana. The Palm and Cycad Society of Australia (PACSOA) reports, from observations made before the description, that plants replanted in different soils can lose their blue sheen, which the new leaves later regain.

Hybrids

No natural hybrid is documented. A grower on the French forum Fous de palmiers mentioned in 2013 garden crosses of Cycas thouarsii with Cycas couttsiana, Cycas cupida and Cycas cairnsiana, intended to produce a fast-growing blue cycad; no other source describes them.

Possible confusion

Ken Hill (1992, 1996) compares the species with Cycas brunnea and Cycas angulata, two species of the southern Gulf of Carpentaria with a similar habit: they are sturdier, carry dark brown hairs, and Cycas angulata is less bluish; their male cones are also larger and almost globular. Among the blue cycads of Queensland, Cycas cupida, its nearest neighbour more than 200 km to the south, has a thicker trunk (20 to 30 cm), rusty-downy new growth, leaflets not narrowed at the base, larger male cones and rusty megasporophylls with a broadly triangular blade (Forster 2001). Cycas cairnsiana has much narrower (2 to 3 mm), rolled leaflets, and Cycas ophiolitica loses its down and has less keeled leaves. Montgomery Botanical Center (2025) groups Cycas couttsiana with Cycas cairnsiana, Cycas cupida, Cycas desolata and Cycas platyphylla in a “Cycas cairnsiana group” of pale-blue species whose morphological similarities make identification difficult.

Taxonomy

Cycas couttsiana is accepted by The World List of Cycads; POWO could not be consulted directly. Ken Hill described it in 1992 in “A preliminary account of Cycas (Cycadaceae) in Queensland”, Telopea 5(1): 197–198. The type was collected on 29 July 1990 by Hill and Stanberg (no. 3738) on Chudleigh Park station, in the Gregory Range, on the upper Stawell River; the holotype is in Sydney (NSW), with isotypes in Brisbane, Canberra, Darwin, Kew and Melbourne. According to the type label, published through GBIF, the plants grew in grassy woodland of Eucalyptus crebra and Corymbia erythrophloia on the steep slopes of a narrow V-shaped valley, in alluvial red sandy loam over sandstone and dolerite, as locally abundant cycads up to 5 m tall with blue, downy leaves.

In his 1996 revision, Hill placed it in series Cairnsianosae (section Cycas, subsection Endemicae), with Cycas cairnsiana, Cycas desolata, Cycas ophiolitica and Cycas platyphylla; Cycas cupida was added in 2001. De Laubenfels and Adema (1998), who adopted much broader species, sank it into the synonymy of Cycas angulata. The World List of Cycads does not follow this view and keeps the species; Hill’s arguments (no dark brown hairs, slenderer habit, smaller male cones) have not been refuted in the sources consulted.

Etymology and history

The epithet honours Pat and David Coutts, owners of Chudleigh Park station and cycad enthusiasts, who brought the plant to Ken Hill’s attention and took steps to protect it on their land (Hill 1992; Haynes 2022). Before its description, the plant circulated under the provisional name Cycas sp. ‘Glen Idle Blue’, after Mrs Coutts’ “Glen Idle” property north of Hughenden (PACSOA, after an article by L. P. Butt published in 1990 in Palms & Cycads).

Common names

No English vernacular name or Aboriginal name could be verified. The only other names in use are the provisional horticultural name ‘Glen Idle Blue’ and the label “Glen Idle Blue Sago” used by the Royal Botanic Garden Sydney, which derives from it.

In the wild

Cycas couttsiana is endemic to Queensland. Hill (1992, 1996) and the Flora of Australia know it from several populations in the southern Gregory Range, in open grassy woodland on red sandy loams derived from basalt or dolerite. An old collection attributed to the Pentland area could not be confirmed.

Herbarium labels published through GBIF give a more detailed picture of these populations: tall grassy woodland of Eucalyptus crebra on flat ground, in deep sandy red loam on basalt, with plants up to 7 m (1990); skeletal red loam on basalt on the rim of a broad valley, with plants up to 4 m (1990); open ironbark and bloodwood woodland on reddish sandy soil at 760 m, with trunked, sometimes multi-headed plants up to 8 m (1995); a population of about 1,000 plants on hillocks along a 700 to 800 m traverse (2003); open forest at 900 m where the species was common over about 1 by 2 km (2003); and, in 2019, open eucalypt forest and grassland on clay soils with basalt outcrops at 746 m. The PACSOA text reports, from “a reliable source”, a very large plant 11.60 m tall and several of about 6 m on the deep soils, for an average height of about 3 m; these figures exceed the botanical description and have not been verified.

Conservation status and regulation

Cycas couttsiana is listed as Near Threatened (NT) by the IUCN: J. D. Bösenberg’s reassessment was published in Red List version 2023-1 (reference checked on Crossref), and the IUCN data relayed by GBIF give it the NT category (consulted on 21 October 2026), as did his first assessment of 2010, cited by The World List of Cycads with criterion B1a. The Flora of Australia, updated in December 2025, gives the same IUCN category and adds that the species is listed as Vulnerable under Queensland’s Nature Conservation (Plants) Regulation 2020 (November 2022 list). In 1992, Hill considered it restricted but not under immediate threat, several populations being large. In 2025, Montgomery Botanical Center reported that the blue cycads of northern Queensland have suffered significant population declines through the collection of plants and seed, driven by their appeal to collectors.

Like every species in the genus except Cycas beddomei, Cycas couttsiana 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 couttsiana

In short: on its own roots it is slow and prone to rot outside warm climates; in Europe a specialist nurseryman ranks it “difficult” and grows it best grafted onto Cycas revoluta, in pots under cover. Full sun, summer heat, a very mineral substrate and a dry winter are the general rules for the blue cycads of Queensland.

Outdoor and in-ground cultivation

The documented open-ground plantings are in Australia and Florida (see below), in climates with long, hot summers. Its habitat, open woodland on red basaltic loams at 750 to 900 m in the dry interior of northern Queensland, points to full sun and a free-draining soil; this is a deduction from the habitat, not a published growing result. In a 2021 note on growing Australian Cycas in a European climate, the French nurseryman Simon Lavaud (Cycadales.eu) places Cycas couttsiana in his “difficult” class, with Cycas cairnsiana, Cycas cupida and Cycas desolata, and sees the complete absence of cold and plenty of water in hot weather as the keys to good growth.

Container cultivation

In the United Kingdom and other temperate regions, it is a plant for a large pot under glass. Simon Lavaud’s general advice for the Australian Cycas is a very mineral substrate (even pure pumice), the brightest possible position, a glasshouse to lengthen the growing season, and generous watering when nights reach 18 to 20 °C (64 to 68 °F) and days 30 °C (86 °F), reduced below 20 °C (68 °F) and stopped when nights fall below 10 °C (50 °F), because of the risk of root rot. The site’s article on his grafting method reports that Cycas couttsiana is the species on which grafting onto Cycas revoluta has been tested most extensively: on container-grown plants kept under shelter, grafted plants grew about five times faster than ungrafted ones, developed a presentable trunk in two to three years instead of about ten, and were no longer prone to root rot. The same article sets out the limits: the rootstock does not pass on its frost tolerance, it produces suckers that must be removed, iron needs increase, and the results apply only to pot culture under cover. On the Italian forum Tropicamente, a grower in Ravenna wrote in 2012 that he would not try the species, fearing the humidity of his region; no growing result from a Mediterranean garden has been published, and the Jardin zoologique tropical at La Londe-les-Maures, in the south of France, has published no observation on it.

In cultivation in the UK, US and Australia

Australia: the Royal Botanic Garden Sydney grows plants of wild origin under accessions S1990-2190 and S2021-0671 (15 plants), labelled “Glen Idle Blue Sago” (Garden Explorer, updated 1 October 2026); a 2015 herbarium voucher from its nursery traces them to Chudleigh Park station. The Australian National Botanic Gardens, in Canberra, declares one accession in BGCI PlantSearch, without saying whether it grows outdoors or under glass.
United States: the online catalogue of Montgomery Botanical Center (Coral Gables, Florida) lists nine accessions, whose numbers date from 1985 to 2022 (six from 2019). Marie Selby Botanical Gardens, in Sarasota, grew the species in the 1990s (herbarium specimens of 1994 and 1997 published through GBIF) and still declares it in BGCI, as does Naples Botanical Garden.
United Kingdom: no record in BGCI PlantSearch or in the British garden catalogues consulted.

In continental Europe, BGCI lists the Jardí Botànic Marimurtra (Blanes, Spain) and the Palmengarten in Frankfurt. 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 couttsiana is dioecious and is raised from seed: a male and a female plant are needed for fertile seed. Seed is occasionally offered by specialist seed merchants; no germination data specific to the species have been published. Grafting onto Cycas revoluta, described above, is a growing technique, not a means of propagation. Seeds are exempt from CITES under annotation #4; given the pressure from collecting in the wild, ask for seed from cultivated plants.

Pests and diseases

Root rot in a cool, wet substrate is the main problem reported in cultivation in Europe (Lavaud 2021; the site’s article on grafting). Like all Cycas, the species is exposed to the Asian cycad scale, Aulacaspis yasumatsui; no pest specific to it is documented.

Cold hardiness

No cold-tolerance value has been published for Cycas couttsiana, and no dated outdoor report of frost damage or survival has been found. The site’s article on grafting stresses that a grafted plant remains as tender above the graft as an ungrafted one, and must be kept under shelter and frost-free in winter.

European experience

No open-ground result has been published in Europe. On the Italian forum Tropicamente, a grower in Ravenna declined to try the species in 2012 for fear of humidity, and another member answered in 2013 that cold, rather than humidity, is the limiting factor; neither reported a trial. The French nurseryman Simon Lavaud keeps his Australian Cycas in barely heated glasshouses and stops watering them from November to March or April. In the absence of data, grow it under glass, frost-free and dry in winter.

United Kingdom, United States and Australia

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

Toxicity and precautions

No toxicity analysis specific to Cycas couttsiana 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 couttsiana has been found in the sources consulted.

Frequently asked questions

Where does Cycas couttsiana come from?

From northern Queensland, Australia: it grows only in the southern Gregory Range, on red soils of basaltic origin, at about 750 to 900 m.

Why is it called couttsiana?

In honour of Pat and David Coutts, owners of Chudleigh Park station, who brought the plant to botanists’ attention and looked after its protection.

Is it really blue?

Yes, but less so than Cycas cairnsiana. Its foliage is a dull blue-green, and plants replanted in other soils can temporarily lose their blue sheen.

Can it be grown outdoors in the UK?

No, on the evidence available. No open-ground trial is documented in a frosty climate; it is grown in a pot under glass, frost-free and dry in winter.

Does grafting make it hardier?

No. According to the site’s article on the Simon Lavaud method, grafting onto Cycas revoluta speeds up growth and limits rot, but the foliage of the grafted plant remains just as sensitive to frost.

Is it a synonym of Cycas angulata?

No, according to The World List of Cycads. De Laubenfels and Adema placed it under Cycas angulata in 1998, but that synonymy is not accepted.

Is it poisonous?

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

Sources

Reference sites

The World List of Cycads (version 2026.08.15), Cycas couttsiana: https://cycadlist.org/scientific_name/112 — author, original publication (Telopea 5(1): 197–198), type (Hill & Stanberg 3738, Chudleigh Park, 1990), range, IUCN status NT, etymology, synonymy of de Laubenfels and Adema. Checklist of the IUCN Cycad Specialist Group, reliable; consulted on 3 October 2026 (unreachable on 21 October 2026).
Flora of Australia, Cycas couttsiana: https://profiles.ala.org.au/opus/foa/profile/Cycas%20couttsiana — description, diagnostic features, distribution, habitat, IUCN NT and Queensland Vulnerable status. National flora (after Hill 1998), reliable; profile updated on 8 December 2025, consulted on 21 October 2026.
GBIF (API), Cycas couttsiana: https://api.gbif.org/v1/species/2683270/iucnRedListCategory — current IUCN Red List category (NT). Reference data infrastructure relaying the Red List; consulted on 21 October 2026.
GBIF, occurrences of Cycas couttsiana: https://www.gbif.org/occurrence/search?taxon_key=2683270 — labels of the type and of specimens from 1990 to 2021 (habitats, altitudes, heights, population sizes); cultivated specimens from Marie Selby Botanical Gardens (1994, 1997) and the Royal Botanic Garden Sydney nursery (2015). Primary herbarium data; consulted on 21 October 2026.
Species+ (UNEP-WCMC), Cycas couttsiana: https://speciesplus.net/species#/taxon_concepts/21538/legal — CITES Appendix II (family listing, annotation #4), EU Annex B. Official CITES and EU database.
Commission Regulation (EU) 2026/1383: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=OJ:L_202601383 — annexes to Regulation (EC) No 338/97 in force since 29 June 2026. Official text.
Palm and Cycad Society of Australia (PACSOA), Cycas couttsiana: https://pacsoa.org.au/wiki/index.php?title=Cycas_couttsiana — provisional name ‘Glen Idle Blue’, reported heights, loss of the blue sheen after transplanting (text by L. P. Butt, 1990). Specialist society; observations made before the description, partly second-hand; consulted on 21 October 2026.
Simon Lavaud (2021), “Quelques données sur les bases de la culture des Cycas australiens en climat européen”, Cycadales.eu: https://cycadales.eu/wp-content/uploads/2021/04/Bases-de-la-culture-des-Cycas-australiens.pdf — Cycas couttsiana in the “difficult” class; general advice on substrate, light and watering. Note by a specialist nurseryman based on his own experience (in French); full text consulted.
Montgomery Botanical News 33(1), spring–summer 2025, “The Search for Australia’s Blue Cycads”: https://www.montgomerybotanical.org/wp-content/uploads/2025/06/Australia2025.pdf — the Cycas cairnsiana group (including Cycas couttsiana), population declines through collection. Botanic garden publication.
Montgomery Botanical Center, living collection catalogue (BG-BASE “Cycads” dataset): https://www.montgomerybotanical.org/research/living-collection/ — nine accessions of Cycas couttsiana (1985–2022). Garden’s own catalogue; consulted on 21 October 2026.
Royal Botanic Garden Sydney, Garden Explorer, Cycas couttsiana: https://rbgsydney.gardenexplorer.org/taxon-2968.aspx — accessions S1990-2190 and S2021-0671, wild origin, label “Glen Idle Blue Sago”. Garden’s own catalogue (updated 1 October 2026).
BGCI PlantSearch: https://plantsearch.bgci.org/ — Australian National Botanic Gardens, Royal Botanic Garden Sydney, Montgomery, Marie Selby, Naples, Marimurtra and Palmengarten Frankfurt declaring the species. Global database of garden lists (declarations, not verified inventories); consulted on 21 October 2026.
Fous de palmiers forum, thread “Cycas panzhihuaensis x debaoensis”: https://www.fousdepalmiers.fr/html/forum/viewtopic.php?p=245698#p245698 — mention of garden crosses with Cycas thouarsii (2013). Growers’ forum (in French); information not corroborated.
Tropicamente forum, thread “Cycas cairnsiana”: https://www.tropicamente.it/forums/topic/cycas-cairnsiana-2/ — Ravenna grower’s reluctance (2012) and reply on cold as the limiting factor (2013). Growers’ forum (in Italian); opinions with no growing result.
ASPCA Animal Poison Control, Sago Palm: https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/sago-palm — toxicity of Cycas revoluta to dogs, cats and horses. Veterinary poison control centre; genus-level information.
NC State Extension Plant Toolbox, Cycas revoluta: https://plants.ces.ncsu.edu/plants/cycas-revoluta/ — cycasin present in all parts of the plant. University extension service; genus-level information.

Bibliography

Hill, K.D. (1992). A preliminary account of Cycas (Cycadaceae) in Queensland. Telopea 5(1): 177–206. doi:10.7751/telopea19924964 [Original description, pages 197–198, fig. 13; key, descriptions and distribution of the Queensland species; full text consulted.]
Hill, K.D. (1996). A taxonomic revision of the genus Cycas (Cycadaceae) in Australia. Telopea 7(1): 1–64. doi:10.7751/telopea19963040 [Revision of the Australian species, series, leaf anatomy, distribution; 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 angulata, page 363; full text consulted.]
Forster, P.I. (2001). Cycas cupida (Cycadaceae), a new species from central Queensland. Austrobaileya 6(1): 153–160. doi:10.5962/p.299661 [Comparison with Cycas cupida and key to series Cairnsianosae; full text consulted.]
Bösenberg, J.D. (2010). Cycas couttsiana. The IUCN Red List of Threatened Species 2010: e.T41973A10614280. doi:10.2305/IUCN.UK.2010-3.RLTS.T41973A10614280.en [First assessment, NT, cited by The World List of Cycads; reference checked on Crossref, page not consulted.]
Bösenberg, J.D. (2023). Cycas couttsiana. The IUCN Red List of Threatened Species 2023: e.T41973A67340954. doi:10.2305/IUCN.UK.2023-1.RLTS.T41973A67340954.en [Current assessment; reference checked on Crossref, NT 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.]