Cycas scratchleyana

Cycas scratchleyana is a large cycad of the humid forests of New Guinea, widespread from south-eastern Papua New Guinea to Indonesian Papua and the Moluccas, with a single plant known in Australia, on Mer (Murray Island) in the Torres Strait. This species of the genus Cycas was described in 1885 by Ferdinand von Mueller, then long confused with Cycas circinalis and Cycas rumphii; Schuster (1932) reduced it to a variety of the former, Cycas circinalis var. scratchleyana. Its long, thin, often wavy leaflets, its petiole spiny along its whole length and the broad, toothed blade of its megasporophylls set it apart. The IUCN lists it as Least Concern.

Key facts about Cycas scratchleyana

  • Accepted name: Cycas scratchleyana F.Muell. (1885), accepted by The World List of Cycads (version 2026.08.15) and by GBIF; POWO could not be consulted
  • Former names and synonyms: Cycas circinalis var. scratchleyana (F.Muell.) J.Schust. (1932), also cited as Cycas circinalis subsp. papuana var. scratchleyana; long misidentified as Cycas circinalis, Cycas rumphii or Cycas media
  • Family: Cycadaceae, order Cycadales
  • Common names: no English name attested; local names in New Guinea and the Moluccas (see Common names)
  • Natural range: Papua New Guinea (Central, Gulf, Milne Bay and Western provinces), Indonesia (Papua, West Papua, Moluccas), Australia (one plant on Mer, Torres Strait, not accepted by Species+)
  • IUCN status: Least Concern (LC), assessment by J.D. Bösenberg dated 2020 and published in Red List version 2023-1; LC according to GBIF
  • CITES and other protection: CITES Appendix II (seeds exempt under annotation #4); Annex B in the European Union
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: in the wild, humid forest, more or less closed, on slopes and ridges, sometimes on stabilised coral sand dunes; no reliable cultivation data
  • Habit and adult size: trunk usually up to 4 m, rarely 7 m (up to 12 m according to the Flora of Australia), 10 to 25 cm across; leaves 1.7 to 3.1 m long
  • In the UK, US and Australia: no botanic garden record found; one wild (or anciently planted) plant on Mer, Queensland
  • Toxicity: no data specific to the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas scratchleyana

Look at the female plants and the leaflets. Cycas scratchleyana has a broad, ovate megasporophyll blade fringed with numerous short to medium lateral spines, long, narrow and thin leaflets without a hypodermis that are often strongly wavy, and a petiole that is usually spiny along its whole length (Lindström et al. 2009; Flora of Australia). The description below follows Lindström, Hill and Stanberg (2009), with additions from the Flora of Australia.

  • Trunk: up to 4 m, rarely 7 m (8 m, rarely 12 m, according to the Flora of Australia), 12 to 20 cm in diameter at its narrowest point (10 to 25 cm according to the Flora of Australia).
  • Leaves: bright to dark green and highly glossy, 1.7 to 3.1 m long, flat in section, with 160 to 300 leaflets and a white down that is shed as the leaf expands.
  • Petiole: 25 to 70 cm long, hairless, spiny for 80 to 100% of its length.
  • Median leaflets: 22 to 31 cm long and 10 to 16 mm wide, strongly two-toned, with slightly recurved, wavy margins and a gently tapering tip; the midrib is raised on both surfaces.
  • Cataphylls: linear and sharp, 5 to 10 cm long.
  • Male cones: narrowly ovoid to spindle-shaped, yellow to pale brown, 20 to 25 cm long and 10 to 13 cm across according to Lindström et al. (35 to 55 cm long according to the Flora of Australia); the apical spine of the microsporophylls is reduced (2 to 6 mm).
  • Megasporophylls: about 28 cm long, orange-brown felted, carrying 2 to 8 ovules; the blade, ovate to lance-shaped, measures 45 to 80 mm by 38 to 50 mm and carries 28 to 40 soft lateral spines, with an apical spine 25 to 30 mm long.
  • Seeds: flattened-ovoid, 43 to 55 mm long and 32 to 40 mm wide; the orange fleshy coat, 5 to 7 mm thick, covers a fibrous layer, and Lindström et al. (2009) found no spongy tissue inside.

The two accounts also differ on the apical spine of the megasporophylls, 25 to 30 mm for Lindström et al. but 8 to 12 mm in the Flora of Australia, which follows Hill (1994).

Hybrids

Lindström et al. (2009) interpret some plants from around Port Moresby, with narrower, harder and slightly keeled leaflets, as the products of hybridisation with Cycas campestris. The Flora of Australia also suggests possible introgression with Cycas seemannii or Cycas bougainvilleana for specimens with broader, harder leaflets, which Lindström et al. attribute rather to a response to strong light. De Laubenfels and Adema (1998) went further and regarded Cycas schumanniana as intermediate between this species and Cycas armstrongii in their broad sense, without testing a hybrid origin.

Possible confusion

Its closest relative is Cycas apoa, from northern New Guinea, whose megasporophyll blade has indistinct or no lateral spines; de Laubenfels and Adema (1998) did not separate the two. In the key by Lindström et al. (2009), Cycas scratchleyana is distinguished from Cycas javana and Cycas montana by a broad megasporophyll blade (more than 35 mm). Cycas papuana, from southern New Guinea, has on the contrary a spineless petiole and bluish young leaves. Plants from the Tanimbar Islands, with a narrower blade, are provisionally included in the species; they may represent regional variation, intergradation with Cycas javana or another taxon.

Taxonomy

Cycas scratchleyana is a name accepted by The World List of Cycads and by GBIF; POWO could not be consulted. Ferdinand von Mueller described it in 1885 in the Victorian Naturalist (2(2): 18–19), from a collection made by W.E. Armit in 1883 during the Argus expedition into the hinterland of Port Moresby (“Mount Bedford, Jala River, Dedouri Country”). The only known specimen, MEL 68059, is accepted as the holotype, with an isotype at Kew (Lindström et al. 2009).

The species was misunderstood for more than a century. Most authors ignored the name and used Cycas circinalis (Lauterbach 1900; White 1922); Thiselton-Dyer (1888) treated it as a form of Cycas rumphii. Schuster (1932) reduced it to a variety of Cycas circinalis within subspecies papuana, which amounted to merging the three subsections of section Cycas into a single species. More recently, the names Cycas rumphii, Cycas circinalis and Cycas media have been applied to it uncritically in herbaria. Hill (1994) reinstated it and placed it in subsection Rumphiae, the cycads with buoyant seeds; de Laubenfels and Adema (1998) also described seeds with a spongy layer. With more complete material, Lindström, Hill and Stanberg (2009) found no spongy tissue and moved the species, with Cycas apoa and Cycas javana, to subsection Cycas, which greatly extends the known range of that group to the east. For the reader, older records of Cycas circinalis or Cycas rumphii from forest in south-eastern New Guinea may refer to this species.

Etymology and history

The epithet honours Sir Peter Henry Scratchley (1835–1885), British military engineer and colonial administrator, Special Commissioner for the territory of New Guinea from 1884 until his death in 1885, the very year of the description (Lindström et al. 2009; Haynes 2022).

In May 2003, B. Wannan and I. Toh collected on Mer (Murray Island), in the Torres Strait, material from a single plant about 15 to 16 m tall, which Forster (2005) identified as this species, a new record for Queensland and Australia (specimen Wannan 2886 & Toh, kept at the Queensland Herbarium, BRI, and the Australian Tropical Herbarium, QRS, according to the Flora of Australia). It grew in sandy soil, in more or less natural vegetation but within a village. Mer lies right next to mainland New Guinea and has close human links with it: Forster considered it feasible that the plant was brought and planted long ago, or grew from seed carried as food, since cycad seeds are eaten by Indigenous peoples in Australia and Papua New Guinea, but thought a natural origin just as possible, the island being close to known populations. The plant’s size, he added, makes a recent planting unlikely. No history of introduction into cultivation is documented.

Common names

No English common name is attested, and the British nursery Trebrown knows of none. Hill (1994), quoted by Lindström et al. (2009), records several local names: bico (Ekor village, Halmahera), enge-enge (Mekeo language, Maipa village), notuweh (Medino village) and kataki (Dsimakani language, Lake Murray area).

In the wild

Cycas scratchleyana is widespread in eastern New Guinea, from near the coast to the foothills, from Milne Bay province to the west of Indonesian Papua and the Moluccas (Aru, Halmahera, Tanimbar), mostly on southern slopes. Often found at altitude (to more than 900 m), it grows on slopes or ridges, in more or less closed humid forest; in the east of its range it also comes down into similar forest on stabilised coral sand dunes and the adjacent headlands (Lindström et al. 2009). De Laubenfels and Adema (1998) record it mainly along watercourses, up to 900 m, sometimes 1,500 m. Collections from Indonesian Papua are scarce, and the species is probably more abundant there than herbaria suggest.

The sources disagree about Australia. The World List of Cycads and the Flora of Australia accept the plant on Mer, in the Torres Strait (see Etymology and history), whereas Species+, the official CITES database, records the species only in Indonesia and Papua New Guinea (consulted on 17 October 2026). The difference concerns a single plant, whose natural origin Forster (2005) and the Flora of Australia consider uncertain.

Conservation status and regulation

The IUCN lists Cycas scratchleyana as Least Concern (LC), in the assessment by J.D. Bösenberg dated 2020 and published in version 2023-1 of the Red List, which replaces that of K.D. Hill (2010); the Red List data relayed by GBIF give the same category (consulted on 24 October 2026). Lindström et al. (2009) did not consider it threatened, whereas the assessment by Donaldson (2003) listed it as Near Threatened (NT) for Indonesia and Papua New Guinea. The Flora of Australia gives no conservation status for the Mer plant, but WildNet, the Queensland Government’s wildlife database, lists the species as Special Least Concern under the Nature Conservation (Animals/Plants) Regulation 2020 and as a restricted plant under the Nature Conservation (Wildlife Management) Regulation 2006, and keeps its records confidential (consulted on 24 October 2026).

Like every species in the genus except Cycas beddomei, Cycas scratchleyana falls under CITES Appendix II, where the family Cycadaceae has been included since 4 February 1977. Annotation #4 (CoP20 version, in force since 5 March 2026) exempts seeds, pollen, seedlings and tissue cultures obtained in vitro and transported in sterile containers, and cut flowers of artificially propagated plants; international trade in the plants themselves requires an export permit. The United Kingdom, the United States and Australia apply CITES through their own legislation; in the European Union the species is in Annex B of Regulation (EC) No 338/97, as 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 information was checked in October 2026 and does not replace the official texts: check the rules in force, ask for proof of origin and prefer plants raised from seed in cultivation.

Growing Cycas scratchleyana

In short: it remains rarely grown, although specialist seed merchants list its seed, and no institution consulted has published growing advice.

Outdoor and in-ground cultivation

The points below are deductions from its habitat, not documented results. A large cycad of humid tropical forest, growing in more or less closed forest up to about 900 m, it is likely to need warmth all year round, humidity, a free-draining soil and some shade or filtered light. Outdoors, only frost-free, humid tropical climates can be considered, such as the wet tropics of Queensland or southern Florida; no garden in these regions has published results for this species. A claim found online that it is one of the most shade-tolerant cycads comes from a seed merchant’s website and is not confirmed by any independent source.

Container cultivation

In the United Kingdom and other temperate regions, the only realistic option is a large pot in a warm, humid glasshouse; its adult size will eventually restrict it to big glasshouses. No European experience exists.

In cultivation in the UK, US and Australia

In short: no botanic garden record found. The species does not appear in the BGCI PlantSearch database or in the online catalogue of Montgomery Botanical Center (both consulted on 24 October 2026), nor in the British, American and Australian catalogues checked in October 2026. In Australia, the only plant on record is the one on Mer, in the Torres Strait (see Etymology and history). The British nursery Trebrown lists the species with a USDA zone 9b rating, its own commercial classification, not a documented trial. No grower’s report was found.

Propagation

The plant is dioecious: seed requires a male and a female plant. No propagation data specific to the species have been published: seed is offered for sale, but no germination time or rate is documented. Seeds are exempt from CITES under annotation #4; look only for seed of legal, documented origin.

Pests and diseases

No pest or disease specific to the species is documented. In cultivation, as with any Cycas, scales such as Aulacaspis yasumatsui can attack it, and overwatering or poor drainage rots the trunk and roots.

Cold hardiness

No cold-tolerance data exist for Cycas scratchleyana. It lives in humid tropical forest, up to more than 900 m, and no source consulted says whether it can take frost.

Mediterranean and European experience

No cultivation result has been published in Europe, in the open ground or in a pot, and no dated frost episode concerns this species.

United Kingdom, United States and Australia

No cold reading was found in any country. The only figure available is Trebrown’s commercial zone 9b rating, which is not based on a published trial. Treat it as a frost-tender plant: a warm glasshouse in the UK, frost-free tropical gardens elsewhere.

Toxicity and precautions

No toxicity study specific to Cycas scratchleyana has been found, but the risk is 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. The ASPCA lists the sago palm (Cycas revoluta) as poisonous to dogs, cats and horses. De Laubenfels and Adema (1998) report that the species is used as food, without describing the preparation; in cycads, seeds can only be eaten after lengthy processing to remove the toxins. In the absence of evidence to the contrary, treat the plant as poisonous: keep seeds and leaves out of reach of children and animals and wear gloves to clean seeds. If any part is swallowed, contact a poison centre, a doctor or a vet straight away.

Traditional uses

De Laubenfels and Adema (1998) state that the species is used as human food, without detailing the parts or preparations. Forster (2005) recalls that cycad seeds are eaten by Indigenous peoples in Australia and Papua New Guinea, which might explain the plant on Mer. No more precise information has been found, and these uses should not be copied.

Frequently asked questions

Where does Cycas scratchleyana grow?

In New Guinea, mainly in the east and south, as far as the Moluccas, in humid forest up to more than 900 m; a single plant is known in Australia, on Mer in the Torres Strait.

Is Cycas scratchleyana a variety of Cycas circinalis?

No. Schuster treated it as such in 1932, but it is a distinct species; Cycas circinalis grows in India.

How does it differ from Cycas apoa?

The megasporophyll blade of Cycas scratchleyana carries clear, numerous lateral spines; that of Cycas apoa has only indistinct ones or none.

Do its seeds float?

No, according to Lindström et al. (2009), who found no spongy tissue in them; earlier authors said otherwise, hence its former place among the cycads with buoyant seeds.

Is it endangered?

No. The IUCN lists it as Least Concern: it is widespread in New Guinea.

Is it native to Australia?

Perhaps. A single tall plant grows on Mer, in the Torres Strait; it may be wild or may have been planted long ago, and Species+ does not include Australia in its range.

Can it be grown outdoors in the UK?

No. It is a plant of humid tropical forest, with no cold data: grow it in a warm glasshouse.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Lindström, A.J., Hill, K.D. & Stanberg, L.C. (2009). The genus Cycas (Cycadaceae) in Indonesia. Telopea 12(3): 385–418. doi:10.7751/telopea20095826 [Description (pp. 392–395), vernacular names, history, transfer to subsection Cycas; full text consulted.]
  • Forster, P.I. (2005). Cycas scratchleyana F.Muell. (Cycadaceae), a new species record for Queensland and Australia. Austrobaileya 7(1): 229–230. [The Mer plant; full text consulted.]
  • Hill, K.D. (1994). The Cycas rumphii complex (Cycadaceae) in New Guinea and the western Pacific. Australian Systematic Botany 7(6): 543–567. doi:10.1071/SB9940543 [Reinstatement of the species, vernacular names; not consulted directly, cited from Lindström et al. (2009) and the Flora of Australia.]
  • Mueller, F. von (1885). [Cycas scratchleyana]. Victorian Naturalist 2(2): 18–19. [Original description; not consulted directly, cited from The World List of Cycads and Lindström et al. (2009).]
  • de Laubenfels, D.J. & Adema, F. (1998). A taxonomic revision of the genera Cycas and Epicycas gen. nov. (Cycadaceae). Blumea 43(2): 351–400. [Very broad species concept, habitat, use as food; full text consulted.]
  • Osborne, R. (2011). Focus on Cycas scratchleyana F.Muell. Encephalartos 103: 9–13. [Review article in the journal of the Cycad Society of South Africa; not consulted, reference found on The World List of Cycads.]
  • Bösenberg, J.D. (2023). Cycas scratchleyana. The IUCN Red List of Threatened Species: e.T42083A69156646. doi:10.2305/IUCN.UK.2023-1.RLTS.T42083A69156646.en [Current assessment (dated 2020); reference found on Crossref, LC category confirmed by GBIF; Red List page not consulted (access blocked).]
  • Hill, K.D. (2010). Cycas scratchleyana. The IUCN Red List of Threatened Species: e.T42083A10624172. [Previous assessment; reference found on The World List of Cycads and Crossref; Red List 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 [Source of the etymologies given by The World List of Cycads; not consulted directly.]
  • 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; consulted directly.]