Cycas rumphii

Cycas rumphii is a large cycad of the shores of eastern Indonesia, centred on the Moluccas, from where it reaches Sulawesi, New Guinea and Christmas Island. It is the type species of a group of coastal cycads with floating seeds, subsection Rumphiae of the genus Cycas, and, like Cycas circinalis, it long served as a catch-all name for the flat-leaved tropical cycads of Asia and the Pacific. In the strict sense it is rare in cultivation: many plants sold under the name belong to other species. It is a plant of frost-free climates, and nothing suggests that it tolerates frost.

Key facts about Cycas rumphii

  • Accepted name: Cycas rumphii Miq. (1839), accepted by The World List of Cycads (version 2026.08.15); the World Checklist of Vascular Plants (WCVP), on which POWO is based, also accepts it (consulted through GBIF on 31 October 2026)
  • Synonyms: Cycas celebica Miq. (1839), according to Lindstrom, Hill and Stanberg (2009) and The World List of Cycads; de Laubenfels and Adema (1998) treated it as a separate species (see Taxonomy)
  • Family: Cycadaceae, order Cycadales; type species of subsection Rumphiae K.D.Hill (1994)
  • Common names: queen sago (a horticultural name also applied to other species); Malayan fern palm (Species+); paku laut, “sea fern”, in Malay (see Common names)
  • Natural range: Indonesia (Moluccas, Sulawesi, Papua, eastern Java, western Kalimantan), northern Papua New Guinea, Australia (Christmas Island, Ashmore Reef)
  • IUCN status: Near Threatened (NT A2cd), assessment by J. D. Bösenberg published in 2023
  • CITES and other protection: CITES Appendix II (seeds exempt under annotation #4); Annex B in the European Union
  • Documented hardiness: no published measurement for the species; plants sold under the name, of uncertain identity, unharmed in Barcelona after several days at about 0 to 1 °C (32 to 33.8 °F) (see Cold hardiness)
  • Light and soil: in the wild, closed woodland and forest near the shore, on more or less calcareous soils; in cultivation, warmth, bright light and a free-draining compost
  • Habit and adult size: trunk usually to 3 m, up to 10 to 12 m, 11 to 40 cm across; glossy leaves 1.5 to 3 m long
  • In the UK, US and Australia: under glass at Cambridge University Botanic Garden (accession of wild origin, 1981) and Edinburgh; Montgomery Botanical Center and Fairchild (Florida); Royal Botanic Garden Sydney (three plants of wild origin)
  • Toxicity: no analysis specific to the species; to be treated as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Cycas rumphii

Cycas rumphii is recognised by its flat, bright green and very glossy leaves with broad, hard leaflets, by male cones whose scales have almost no point, and by seeds with a ridge at the top of the shell and a spongy layer that makes them float (Lindstrom, Hill and Stanberg 2009; de Laubenfels and Adema 1998).

The trunk is usually up to 3 m tall, rarely 10 m, and 11 to 20 cm across at its narrowest point according to Lindstrom, Hill and Stanberg (2009); de Laubenfels and Adema (1998), whose concept of the species was broader, give up to 12 m and 20 to 30 (40) cm, often branched. The leaves, 150 to 250 cm long, are flat: the opposite leaflets are inserted at 180° on the rachis. Each leaf carries 150 to 200 leaflets and is covered in an orange down that falls as it expands. The petiole, 35 to 60 cm long, is spiny over a variable length, often all along. The median leaflets are 22 to 32 cm long and 12 to 16 mm wide, clearly paler beneath, often curved, with slightly rolled margins and a soft tip. The cataphylls are narrowly triangular and soft.

The male cones, spindle-shaped and yellow to pale brown, are 35 to 55 cm long and 10 to 15 cm across; each microsporophyll has only a rudimentary, upturned point 2 to 5 mm long. The megasporophylls, 18 to 32 cm long, are covered in white or yellow felt; they carry 2 to 6 ovules and a lanceolate blade 50 to 75 mm long, barely toothed, with about twelve soft teeth 0 to 4 mm long and a slender tip 10 to 25 mm long. The seeds, flattened-ovoid and about 45 mm by 30 mm, have orange-brown flesh; the shell bears a ridge at the top and covers a spongy layer (Lindstrom, Hill and Stanberg 2009).

Hybrids

No natural hybrid of Cycas rumphii has been described. Lindstrom, Hill and Stanberg (2009) do, however, suggest possible gene mixing with Cycas bougainvilleana in the east of its range, to explain variation in leaflet anatomy. No documented garden hybrid has been published.

Possible confusion

A name long applied to other cycads

Miquel described Cycas rumphii in 1839 from the plates of Rumphius, without ever clearly defining its limits. The name was then applied, alongside or instead of Cycas circinalis, to almost all the flat-leaved tropical cycads of South-East Asia and the Pacific: Pilger (1926) placed all the Indonesian taxa under it, and Schuster (1932) added subspecies and varieties now assigned to other species (Lindstrom, Hill and Stanberg 2009). The name Cycas rumphii subsp. zeylanica, for example, refers to a plant from Sri Lanka, now Cycas zeylanica (Lindstrom and Hill 2007).

In cultivation, the confusion goes on. According to recent revisions, the species in the strict sense is rare. A specialist nurseryman pointed out on the French forum Fous de palmiers in 2020 that Cycas rumphii grows only in the Moluccas and Sulawesi, that it is very rare in cultivation, and that all the “circinalis” and “rumphii” he had seen for sale in Europe were Cycas thouarsii. Conversely, at the Royal Botanic Garden Edinburgh, an inventory published in 2010 re-identified as Cycas rumphii several plants labelled Cycas circinalis.

Telling it from related species

  • Cycas thouarsii, from Madagascar and East Africa: microsporophylls ending in a clearly hooked point 5 to 8 mm long, red seeds 54 to 60 mm long with no ridge described, narrower leaflets (8 to 13 mm) according to de Laubenfels and Adema (1998).
  • Cycas seemannii, from Fiji, Tonga, Vanuatu and New Caledonia: petiole with few or no spines and narrower leaflets; de Laubenfels and Adema (1998), who placed it in Cycas celebica, give it larger seeds (55 to 70 mm) with a weak ridge.
  • Cycas edentata, from the coasts of the Philippines, Malaysia and Thailand: seeds without a ridge and microsporophylls with a long point, at least 12 mm (de Laubenfels and Adema 1998; Lindstrom, Hill and Stanberg 2009).
  • Cycas scratchleyana, from the forests of the Moluccas to New Guinea: less tapering leaflets and smaller seeds with a weak ridge; Rumphius’s plate 22, long cited as the type, resembles it (Lindstrom, Hill and Stanberg 2009).
  • Cycas circinalis, from India: seeds without a spongy layer and microsporophylls ending in a long point 20 to 39 mm long.

Taxonomy

Miquel published Cycas rumphii in 1839, based on the “Olus calappoides” or “Sajor calappa” of Rumphius’s Herbarium Amboinense (1741). Rumphius’s specimens having been lost in a shipwreck, Miquel relied on plates 22 (female plant) and 23 (male plant). These two plates in fact show two species: plate 22 resembles Cycas scratchleyana. Lindstrom (2002) designated plate 23 as the lectotype, in line with current usage of the name and with a recent collection from Ambon (Lindstrom, Hill and Stanberg 2009). The World List of Cycads accepts this lectotype.

Hill (1994) created subsection Rumphiae for the Cycas rumphii group in New Guinea and the western Pacific. He recognised six species in it, three of them new (Cycas bougainvilleana, Cycas apoa and Cycas micronesica), alongside Cycas rumphii, Cycas scratchleyana and Cycas seemannii (from the abstract of the article; full text not consulted). The subsection is defined by a spongy layer inside the seed; seed maturation over two years has been confirmed in Cycas seemannii, Cycas thouarsii and Cycas bougainvilleana (Lindstrom, Hill and Stanberg 2009).

De Laubenfels and Adema (1998) proposed a different arrangement. They placed Cycas rumphii in a subgenus Truncata, defined by truncate microsporophylls, included Cycas bougainvilleana in it, regarding it as based on unreliable characters, and recognised Cycas celebica as a separate species with a weakly spiny petiole, placing Cycas seemannii and Cycas micronesica in it. Lindstrom, Hill and Stanberg (2009), on the contrary, returned Cycas celebica to the synonymy of Cycas rumphii: the lack of spines on the petiole, visible on the type plate, varies within the populations of Sulawesi. The World List of Cycads, which this site follows, adopts this treatment and accepts Cycas bougainvilleana, Cycas seemannii and Cycas micronesica as separate species.

Etymology and history

The epithet honours Georg Eberhard Rumpf, known as Rumphius (1628–1702), a German-born naturalist in the service of the Dutch East India Company on Ambon (Haynes 2022; Lindstrom, Hill and Stanberg 2009). The Latin name he gave the plant, “Olus calappoides”, literally means “coconut-like vegetable”.

Roxburgh was the first, in 1832, to recognise a distinct Malesian cycad among the plants grown at the Calcutta botanic garden, but he treated it under the name Cycas circinalis. After Miquel, Stapf (1916) summarised the debates about the species, and Schuster (1932) gave a treatment that Lindstrom, Hill and Stanberg (2009) describe as “essentially correct”, apart from his varieties and subspecies. Naming errors nevertheless persisted even in reference works: Jones (1993) still illustrated the species as Cycas circinalis, an error corrected in his second edition (2002).

Common names

In English, the species is called queen sago (Lindstrom, Hill and Stanberg 2009), a name also used in Florida for other large tropical cycads; the Royal Botanic Garden Sydney labels it “Queen Sago Palm”, and Species+ gives Malayan fern palm. In Malay, the names recorded by Hill (1994) and repeated by Lindstrom, Hill and Stanberg (2009) include pakoe laut or paku laut, “sea fern”, paku gajah, haji and intalappana; in Biak, nufuès. The name namwele and the sacred status reported from Vanuatu do not concern this species: Vanuatu lies outside the range of Cycas rumphii according to The World List of Cycads and belongs to the range of Cycas seemannii.

In the wild

As understood by Lindstrom, Hill and Stanberg (2009), Cycas rumphii has a range centred on the Moluccas. It reaches Indonesian Papua and part of the north coast of Papua New Guinea to the east, Sulawesi to the north, and southern Borneo, north-eastern Java and Christmas Island to the west. The World List of Cycads also cites Ashmore Reef, where seeds have been found washed up on the beach, probably from Indonesia, as well as East New Britain and New Ireland. De Laubenfels and Adema (1998) extended the species to the Solomon Islands, the Marshall Islands and the Carolines by including Cycas bougainvilleana. Species+, which follows an older concept, still lists India, Malaysia, the Philippines, Singapore and Thailand.

The species grows mainly in closed woodland and forest on more or less calcareous soils near the shore (Lindstrom, Hill and Stanberg 2009). Its seeds float, which favours dispersal by sea; according to de Laubenfels and Adema (1998), people have also carried it, which would explain some isolated sites.

Conservation status and regulation

The IUCN lists Cycas rumphii as Near Threatened (NT A2cd), in the assessment by J. D. Bösenberg published in 2023 (category checked on GBIF and The World List of Cycads). The previous assessment, by K. D. Hill, dates from 2010; Donaldson (2003) had already listed it as NT. Lindstrom, Hill and Stanberg (2009) explain that, once abundant, it occupies coastal sites under heavy pressure from population growth, development and aquaculture: it is probably not threatened in the short term, but could become so. The 2023 assessment carries a new IUCN identifier; it may cover a broader concept including Cycas celebica, which could not be checked.

Like the whole Cycadaceae family, the species has been listed in CITES Appendix II since 4 February 1977, with annotation #4 (CoP20 version, in force since 5 March 2026): seeds, pollen and seedlings in sterile containers are not covered by CITES. In the European Union it falls under Annex B of Regulation (EC) No 338/97 (annexes set by Regulation (EU) 2026/1383, in force since 29 June 2026). Check the regulations in force before any purchase or exchange, and prefer plants raised from seed in cultivation.

Growing Cycas rumphii

No growing guide specific to Cycas rumphii in the strict sense has been published. Its natural habitat, humid tropical coastal forest with no cold season, points to a plant for the tropics or for a heated glasshouse elsewhere: this is a deduction from the habitat, which the few growing reports confirm.

Outdoor and in-ground cultivation

Outdoors, it can only be considered in frost-free tropical and near-tropical climates, such as southern Florida, where the University of Florida has recorded it in gardens in Miami-Dade County (see Pests and diseases). In Europe, the only reports of plants sold under the name in the ground come from Barcelona and Ischia (see Cold hardiness), and their identity has not been checked.

Container cultivation

In a container, give it a very free-draining compost, bright light, warmth all year round, regular watering in summer and less in winter. At Cambridge University Botanic Garden, the species has been grown under glass since 1981. A report published by the Royal Botanic Garden Edinburgh in 2010 put the growth problems and diseases of its cycad collection down to positions that were too wet and poorly drained. Plants sold in garden centres under this name, most often Cycas thouarsii according to the nurseryman quoted above, need the same care.

In cultivation in the UK, US and Australia

  • United Kingdom: Cambridge University Botanic Garden grows an accession of wild origin received in 1981 (year taken from the accession number), under glass; at Edinburgh, the 2010 inventory re-identified several “Cycas circinalis” as Cycas rumphii. Kew, Oxford, Glasgow, Wisley, Paignton Zoo and Treborth, among others, declare it to BGCI PlantSearch.
  • United States: Montgomery Botanical Center lists three accessions in its online catalogue and Fairchild Tropical Botanic Garden also lists it; the Huntington, Lotusland, the San Diego Botanic Garden, the San Diego Zoo, the Missouri Botanical Garden, Naples Botanical Garden, UC Berkeley and others declare it to BGCI PlantSearch.
  • Australia: the online catalogue of the Royal Botanic Garden Sydney (consulted on 21 October 2026) lists three plants of wild origin in bed 82c, one from the Philippines (1993) and two from Indonesia (1999); a wild origin in the Philippines falls outside the range accepted for the species, so the identity of that plant is open to question. The Royal Botanic Gardens Victoria, the Australian National Botanic Gardens and Adelaide declare it to BGCI PlantSearch.

Given the history of the name, any garden list should be read with caution, and a BGCI entry shows only that a garden has listed the species at some point.

Propagation

Cycas rumphii is propagated from seed; a male and a female plant are needed. Its seeds have a spongy layer that makes them float. No germination protocol specific to the species has been published. Seeds are exempt from CITES.

Pests and diseases

The University of Florida has recorded the Asian cycad scale, Aulacaspis yasumatsui, on Cycas rumphii in Miami-Dade County, where an infested leaf was photographed (Weissling, Howard and Hamon, fact sheet EENY-096). The species is also among the hosts of the butterfly Chilades pandava in South-East Asia. Like all cycads, it can rot if the compost stays wet in cool weather.

Cold hardiness

No cold-hardiness measurement has been published for Cycas rumphii in the strict sense, and plants sold under the name are of uncertain identity. Treat it as a frost-tender plant.

Mediterranean experience

In Barcelona, a gardener reports on the Fous de palmiers forum (October 2010) that six plants sold under this name, in the ground for four years, came through the snow of the previous winter and several days at about 0 to 1 °C (32 to 33.8 °F) without damage to the leaves. In Italy, on the island of Ischia, a gardener whose night-time minima do not usually fall below 4 °C (39.2 °F) planted one in the ground in January 2010 (Tropicamente forum). In south-east France, a gardener on the Côte Bleue (Bouches-du-Rhône) said in 2010 on the Fous de palmiers forum that he had none in the ground and that temperatures below zero could be fatal to it. No result in the ground has been published elsewhere in France, and the Jardin zoologique tropical at La Londe-les-Maures (Var) has published no observations on the species. None of these plants has been identified by a botanist.

United Kingdom, United States and Australia

No growing report from the three countries has been published. In the UK the species is grown only under glass. In the United States, outdoor cultivation is documented only in southern Florida (University of Florida). In Australia, the Royal Botanic Garden Sydney grows plants of wild origin in its garden beds, but no frost data are documented.

Toxicity and precautions

No toxicity analysis specific to Cycas rumphii has been published, but all the Cycas species studied contain cycasin, which is converted in the body into methylazoxymethanol, toxic to the liver and nervous system, along with a neurotoxic amino acid, BMAA, especially in the seeds (NC State Extension; ASPCA). The ASPCA lists Cycas revoluta as toxic to dogs, cats and horses. Treat the plant as poisonous: keep seeds out of reach of children and pets, wear gloves to handle them and, if any part is swallowed, contact a poison centre, a doctor or a vet straight away.

Traditional uses

The published sources describe no specific traditional use of Cycas rumphii. The name Rumphius gave it, “coconut-like vegetable”, suggests that the plant was eaten on Ambon, but no published source confirms this. In any case, such preparations must not be copied.

Frequently asked questions

Is my garden-centre Cycas rumphii a true Cycas rumphii?

Probably not. The species in the strict sense is rare in cultivation in Europe; according to a specialist nurseryman, plants sold under the name are most often Cycas thouarsii.

How can I recognise Cycas rumphii?

Mainly by its reproductive organs: male cone scales almost without a point (2 to 5 mm) and seeds with a spongy layer and a ridge at the top of the shell. Its leaflets, 12 to 16 mm wide, are very glossy.

Where does it come from?

From the shores of eastern Indonesia, mainly the Moluccas, Sulawesi and Papua, to northern Papua New Guinea and Christmas Island.

How does it differ from Cycas thouarsii and Cycas seemannii?

Cycas thouarsii, from Africa, has microsporophylls with a hooked point 5 to 8 mm long and red seeds with no ridge described; Cycas seemannii, from Fiji and nearby islands, has a weakly spiny petiole and narrower leaflets according to de Laubenfels and Adema (1998), who did not separate it from Cycas celebica.

Can it take frost?

No. No measurement has been published, and plants sold under the name remain tropical plants. Outside the tropics, keep it frost-free in winter, ideally in a heated glasshouse.

Is it endangered?

It is listed as Near Threatened by the IUCN (2023): its coastal habitats are under pressure from population growth, development and aquaculture.

Is it poisonous?

It must be assumed so. No specific analysis exists, but all the cycads studied contain serious toxins, especially in the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Miquel, F.A.W. (1839). Bulletin des Sciences Physiques et Naturelles en Néerlande 2: 45. [Protologue of Cycas rumphii and Cycas celebica; reference checked on The World List of Cycads.]
  • Rumphius, G.E. (1741). Herbarium Amboinense 1: 86–87, t. 20–23. Amsterdam. [Type plates; cited after Lindstrom, Hill and Stanberg 2009.]
  • 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 [Subsection Rumphiae, six species.]
  • de Laubenfels, D.J. & Adema, F. (1998). A taxonomic revision of the genera Cycas and Epicycas gen. nov. (Cycadaceae). Blumea 43(2): 351–400. [Subgenus Truncata, description, key, Cycas celebica separate with Cycas seemannii in synonymy.]
  • Lindstrom, 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, lectotypification, Cycas celebica in synonymy, range, habitat, conservation, vernacular names.]
  • Lindström, A.J. & Hill, K.D. (2007). The genus Cycas (Cycadaceae) in India. Telopea 11(4): 463–488. doi:10.7751/telopea20075745 [Cycas rumphii subsp. zeylanica assigned to Cycas zeylanica; megasporophyll of Cycas circinalis.]
  • Bösenberg, J.D. (2023). Cycas rumphii. The IUCN Red List of Threatened Species 2023: e.T216470283A69156062. doi:10.2305/IUCN.UK.2023-1.RLTS.T216470283A69156062.en [Current assessment (NT); reference checked on Crossref.]
  • Hill, K.D. (2010). Cycas rumphii. The IUCN Red List of Threatened Species 2010: e.T42081A10623127. doi:10.2305/IUCN.UK.2010-3.RLTS.T42081A10623127.en [Previous assessment; reference checked on Crossref.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. doi:10.11646/phytotaxa.550.1.1 [Etymology; used through The World List of Cycads.]
  • 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.]