The genus Cycas, the sago palm and its relatives

Cycas revoluta
Cycas revoluta

The genus Cycas brings together the cycads of Asia, Oceania and East Africa. It is the only genus in the family Cycadaceae and the largest in the whole order: The World List of Cycads, the reference checklist for the group, recognises 118 species and 6 subspecies in its version of 15 August 2026. These palm-like plants range from southern Japan and China to northern Australia, and from the coasts of Kenya and Madagascar to Fiji and Tonga. One feature sets the genus apart from every other living cycad: female plants do not form a cone but a crown of fertile leaves that carry the seeds along their edges. The genus includes the most widely grown cycad in the world, Cycas revoluta, the sago palm, and two species of particular interest to gardeners in cooler climates for their cold tolerance, Cycas panzhihuaensis and Cycas taitungensis. Two genus names now abandoned, Epicycas and Dyerocycas, refer to plants placed in Cycas. Every species is protected under CITES, and more than six in ten are classed as threatened by the IUCN.

Key facts about Cycas

  • Accepted name: Cycas L., published by Linnaeus in 1753 in Species Plantarum: 1188; type species Cycas circinalis L.
  • Number of species: 118 species and 6 subspecies, i.e. 124 accepted taxa (The World List of Cycads, version 2026.08.15)
  • Family: Cycadaceae, of which Cycas is the only genus; it is the sister lineage of all other cycads, which are grouped in the Zamiaceae
  • Former genus names: Epicycas de Laub. and Dyerocycas Nakai, synonyms of Cycas
  • Common names: sago palm, king sago and Japanese sago palm for Cycas revoluta; emperor sago for Cycas taitungensis; queen sago for Cycas circinalis; sotetsu in Japanese (see Common names)
  • Natural range: from Japan (Ryukyu Islands) and southern China to India, South-East Asia, Australia, New Guinea and the Pacific islands; one species in East Africa, Madagascar and the Comoros
  • IUCN status: 20 species Critically Endangered (CR), 26 Endangered (EN), 27 Vulnerable (VU), 15 Near Threatened (NT), 23 Least Concern (LC) and 7 Not Evaluated (NE), according to The World List of Cycads and the species assessments; assessments published between 2010 and 2024
  • CITES: the whole genus in Appendix II since 4 February 1977, with annotation #4, which exempts seeds among other things; Cycas beddomei in Appendix I since 22 October 1987; Annexes B and A in the European Union
  • Documented hardiness: Cycas revoluta often loses its leaves at around −6 to −9 °C (21.2 to 15.8 °F), but its trunk can regrow after −10 to −14 °C (14 to 6.8 °F) in dry soil; University of Florida extension rates it for USDA zones 8 to 11 and the RHS rates it H3 in the UK; Cycas panzhihuaensis kept intact foliage at −12 °C (10.4 °F) with almost no protection near Paris in winter 2008–2009; most other species do not tolerate frost (see Cold hardiness)
  • Light and soil: full sun to partial shade, very free-draining soil, moderate watering in summer, soil almost dry in winter
  • Habit: from small plants with an underground stem to shrubs with trunks several metres tall; Cycas revoluta reaches 1 to 3 m, rarely 7 m (Hill, 2008)
  • Toxicity: all parts are poisonous, the seeds above all; potentially fatal to dogs (see Toxicity and precautions)

Characteristics of the genus Cycas

A Cycas is recognised first by its leaflets, which have a single thick midrib and no side veins, and by its female plants, which bear no cone. According to the description of the genus published by The World List of Cycads:

  • Habit: dioecious plants, meaning that the sexes are on separate plants, palm-like, with a thick cylindrical stem, above or below ground, clad in the bases of old leaves.
  • Leaves: pinnate, rarely bipinnate, arranged in a spiral and produced in successive flushes separated by cataphylls, leaves reduced to scales. The lowest leaflets are often reduced to spines. Young leaves are hairy.
  • Leaflets: rolled inwards in the bud like a fern fiddlehead, with a single midrib and stomata almost always confined to the lower surface.
  • Male organs: true cones, made of fertile scales (microsporophylls) whose tip often ends in an upturned spine.
  • Female organs: fertile leaves (megasporophylls) arranged in a rosette at the top of the stem, which then carries on growing. Each bears two to several ovules along its edges and ends in a blade that is comb-like, toothed or entire.
  • Seeds: almost round to ellipsoid, with a fleshy yellow, orange or brown coat, and sometimes a spongy tissue beneath the hard shell.

No female cone: a crown of fertile leaves

This is the trait that separates Cycas from all other living cycads. In the Zamiaceae, such as Encephalartos, Zamia or Dioon, the ovules are carried on the scales of a compact cone. In Cycas, the megasporophylls are genuine modified leaves, often covered in brown or yellowish down, gathered in a crown at the centre of the plant. Their axis does not stop: after the reproductive season the stem resumes growth and produces new leaves above them. In some species these fertile leaves stay loose and well separated; in others they are packed into a rounded mass that looks like a cabbage. K. D. Hill describes the female plants of Cycas taitungensis in this way, as more tightly packed than those of Cycas revoluta. The shape of the megasporophyll blade, comb-like or entire, is also used to classify the species (see Taxonomy).

Cycas panzhihuaensis
Cycas panzhihuaensis, female plant grown at the Jardin zoologique tropical (La Londe-les-Maures, Var, France)

A Cycas or a palm?

Despite their habit and the name “sago palm” given to Cycas revoluta, Cycas are not palms. They are gymnosperms, seed plants with naked seeds like conifers, whereas palms are flowering plants, as the University of Florida extension service (UF/IFAS) points out. The word “sago” originally refers to an edible starch; true commercial sago comes mainly from a palm, Metroxylon sagu, according to the same source.

Taxonomy and classification

Cycas is an accepted genus and the only member of the family Cycadaceae. K. D. Hill noted in 2008 that this family is the oldest lineage of living cycads, and that Cycas is the only cycad genus native to Asia. The World List of Cycads, edited by Michael Calonje, Dennis Stevenson and Roy Osborne for Montgomery Botanical Center, recognises 118 species and 6 subspecies in its version 2026.08.15: three subspecies of Cycas maconochiei and three of Cycas media, all in Australia. Kew’s World Checklist of Vascular Plants, on which POWO (the site’s nomenclatural authority) is based, differs at least over Cycas taitungensis (see below). Two genus names, Epicycas de Laubenfels and Dyerocycas Nakai, are treated as synonyms.

K. D. Hill’s six sections

Yes, the genus is divided into sections, and the classification rests mainly on the reproductive organs. Hill defined four in 1995; a fifth, Wadeae, was created in 2008 for Philippine species by Lindström, Hill and Stanberg, and a sixth, Panzhihuaenses, by Hill in the same year. According to the key and descriptions published by Hill (2008):

  • Section Asiorientales J.Schust. (1932), type species Cycas revoluta: hairy ovules, firm waxy male cones, red seeds, deeply sunken stomata. A relict group of two very close species, Cycas revoluta and Cycas taitungensis.
  • Section Panzhihuaenses (D.Yue Wang) K.D.Hill (2008): hairless ovules, waxy male cones, red to orange seeds. It contains only Cycas panzhihuaensis, from south-western China.
  • Section Stangerioides Smitinand (1971), type species Cycas micholitzii: soft male cones, yellow seeds with a warty shell. The most complex group, which brings together most Chinese species, from northern Thailand and Myanmar to Laos, Vietnam and southern China.
  • Section Indosinenses J.Schust. (1932), type species Cycas siamensis: hard or woody male cones, a large, deeply comb-like megasporophyll blade, a fibrous layer in the seed coat. From the Indian Himalaya and Nepal to Vietnam and southern China, and down to the north of the Malay Peninsula.
  • Section Cycas: hard male cones, megasporophyll blade entire or toothed, not comb-like. It includes the type species of the genus, Cycas circinalis, and is not represented in China.
  • Section Wadeae (2008): a relict section confined to the Philippines, with Cycas wadei, Cycas curranii and Cycas saxatilis (Lindström, Hill and Stanberg, 2008).

These sections largely follow geography. That is why the species list further down is arranged by region, with the section given only where a published source states it.

What genetic studies show

The study by Liu and colleagues (2018, Molecular Phylogenetics and Evolution), carried out at the Kunming Institute of Botany on 90 % of the species, broadly confirms Hill’s classification: the genus falls into thirteen lineages and six sections. Sections Panzhihuaenses and Asiorientales together form the oldest branch, with partial statistical support. Section Stangerioides is not a natural group in the strict sense: its species form a grade. Section Indosinenses also includes two species of section Cycas, Cycas macrocarpa and Cycas pranburiensis. Finally, section Cycas is the youngest, and its subgroups match geography.

Living species are young. The study by Nagalingum and colleagues (2011, Science) shows that cycads diversified again almost everywhere from the late Miocene onwards, and that living species are hardly more than 12 million years old. The group is ancient, but today’s Cycas are not “living fossils” in the strict sense.

Names that have changed

Several names still used in cultivation, or on this site, are no longer accepted by The World List of Cycads. For the reader, this means that a plant bought or described under one of these names belongs to the species shown:

  • Cycas hainanensis, Cycas lingshuiensis and Cycas shanyaensis, described from Hainan Island, are placed under Cycas taiwaniana. In 2008 Hill still accepted Cycas hainanensis and Cycas shanyaensis, and placed Cycas lingshuiensis, originally published with the misspelling “lingshuigensis”, in the synonymy of Cycas hainanensis. Their transfer to Cycas taiwaniana follows the molecular study by Feng and colleagues (2021, Taxon), which recognises only two species in the Cycas taiwaniana complex and includes Cycas hainanensis and Cycas lingshuiensis in Cycas taiwaniana. Cycas changjiangensis, once treated as a subspecies of Cycas hainanensis and also absorbed into Cycas taiwaniana by that study, remains a species in its own right for The World List of Cycads.
  • Cycas fairylakea, described in 1996, is placed under Cycas szechuanensis.
  • Cycas andamanica, described in 2015 from the Andaman Islands, is a synonym of Cycas pschannae, published the same year.
  • Cycas darshii is a synonym of Cycas sphaerica, and Cycas sainathii a synonym of Cycas zeylanica.
  • Cycas miquelii, which de Laubenfels placed in a separate genus, Epicycas, is according to Hill (2008) merely a form of Cycas revoluta without spines on the petiole.
  • Cycas longipetiolula refers to natural hybrids between Cycas bifida and Cycas multipinnata in Yunnan (Hill, 2008). Cycas multifrondis, described from a cultivated plant, was also regarded by Hill (2008) as a hybrid form, between Cycas dolichophylla and Cycas bifida; The World List of Cycads nevertheless accepts it today as a species, in line with Chen, Yang and Li (2014), who treat it as an independent species according to Zheng and colleagues (2017).

Cycas taitungensis or Cycas revoluta? The sources disagree. The World List of Cycads accepts Cycas taitungensis, described in 1994 from south-eastern Taiwan, and Hill (2008) separates it from Cycas revoluta by its longer, flatter leaves, longer leaflets, more tightly packed female cones and darker seeds. Kew’s World Checklist of Vascular Plants, the basis of POWO (dataset published on GBIF, June 2026 version), on the contrary treats it as a synonym of Cycas revoluta, without giving a reason. This site keeps Cycas taitungensis as a distinct species, an editorial choice based on the differences seen in cultivation; POWO remains the site’s botanical reference.

Etymology and history of the genus

The name Cycas comes from the Greek koikas, the name of a kind of palm, according to The World List of Cycads. Linnaeus published the genus in 1753 with Cycas circinalis, whose type is a plate in Rheede’s Hortus Malabaricus (1682), devoted to the plants of the Malabar Coast in south-western India. The epithet circinalis refers to the young leaflets coiled like a crozier. Thunberg described Cycas revoluta in 1782 from plants from Japan; its name comes from the Latin revolutus, “rolled back”, because the leaflet margins are rolled under (Haynes, 2022).

The number of species has grown considerably since the 1990s. Hill counted about 100 species in 2008. For China alone, he notes that four of the twenty-two species he recognised had been described before 1975, and that some thirty new names had been created since, many of them now regarded as superfluous. Recent descriptions concern mainly India, the Philippines and Australia: Cycas flabellata and Cycas mindanaensis date from 2019, Cycas divyadarshanii from 2020.

Common names

In English, “cycad” is used for the whole order, while the common names of the genus apply to a handful of cultivated species. The attested names are:

  • English: sago palm, king sago and Japanese sago palm for Cycas revoluta (Hill, 2008; UF/IFAS; the Royal Horticultural Society uses Japanese sago palm); emperor sago for Cycas taitungensis (Hill, 2008; UF/IFAS); queen sago for Cycas circinalis (UF/IFAS).
  • Japanese: sotetsu for Cycas revoluta; Hill (2008) also records some thirty regional names in the Ryukyu Islands.
  • Chinese: tieshu (“iron tree”) and su-tie for Cycas revoluta; Panzhihua su-tie for Cycas panzhihuaensis; tai-dong su-tie for Cycas taitungensis (Hill, 2008).

These names are confusing. “Sago” and “sago palm” are also applied to true palms, including Metroxylon sagu, and “queen sago” refers, depending on the source, to several large tropical species. No established English name is attested for the other species of the genus.

Distribution and ecology

Cycas has the widest range of any cycad genus, from East Africa to the western Pacific. According to the distributions published by The World List of Cycads, the richest countries are Australia (34 species, 31 of them endemic), Vietnam (27), China including Taiwan (22), India (14), the Philippines (13), Thailand (12), and Indonesia and Laos (10 each). By region:

  • Japan and China: Cycas revoluta in the Ryukyu Islands, Cycas taitungensis in the mountains of southern Taiwan, and some twenty species in southern China, often shared with northern Vietnam.
  • Indochina: Vietnam, Laos, Cambodia, Thailand and Myanmar form, with southern China, the great Asian centre of diversity.
  • India and Sri Lanka: thirteen species, from the Western and Eastern Ghats to the eastern Himalaya and the Andaman and Nicobar Islands.
  • Malaysia and Indonesia: species spread from the Malay Peninsula to Java, the Lesser Sunda Islands and the Moluccas; the Philippines add twelve species of their own.
  • Australia: thirty-one species endemic to the north of the country, in Queensland, the Northern Territory and Western Australia.
  • Pacific: from New Guinea to the Solomon Islands, Micronesia, Vanuatu, New Caledonia, Fiji and Tonga.
  • East Africa and Madagascar: a single species, Cycas thouarsii, in Kenya, Tanzania, Madagascar and the Comoros.

Hill (2008) describes Cycas as understorey shrubs of forest, open woodland and savanna. The habitats of the species most often grown in gardens differ widely. Cycas revoluta grows in the Ryukyu Islands on steep, stony slopes; its natural occurrence on the coast of Fujian is likely but has not been confirmed recently. Cycas taitungensis lives on steep slopes in the mountains of southern Taiwan; its type was collected at about 500 m, in a reserve created for it. Cycas panzhihuaensis occupies low woodland and dry thickets, on slopes that are often limestone, in the hot, dry valleys of the Jinsha, Yalong and Anning rivers in southern Sichuan and northern Yunnan; a 2026 study shows that January surface temperature is the factor that most limits its range (Yang et al., 2026, Plants).

Some species are dispersed by the sea. Their seeds have a spongy tissue beneath the shell that makes them float: The World List of Cycads records this tissue in part of the genus, and Mankga and colleagues (2020) see it as the innovation that allowed the colonisation of the Pacific islands. That study places the origin of the genus in Indochina; Hill (2008), relying on Eocene fossils found in China and Japan, places it more broadly in mainland Asia.

Conservation status and regulation

Every species of Cycas is protected under CITES. According to Species+, the official database for CITES and the European Union, the family Cycadaceae has been listed in Appendix II since 4 February 1977. A single species, Cycas beddomei, endemic to Andhra Pradesh in India, was moved to Appendix I on 22 October 1987; it was previously in Appendix II. The Appendix II listing carries annotation #4, whose current version dates from 5 March 2026 (CoP20). For cycads, it exempts from CITES:

  • seeds, spores and pollen;
  • seedlings and tissue cultures obtained in vitro and transported in sterile containers;
  • cut flowers of artificially propagated plants.

Live plants, even young ones, therefore still need CITES permits in international trade; seeds do not, except those of Cycas beddomei, because Appendix I carries no exemption. The United Kingdom, the United States and Australia apply CITES through their own national legislation and permit systems; check with the national CITES authority before importing or exporting a plant. For readers in the European Union, the genus is listed in Annex B of Regulation (EC) No 338/97 and Cycas beddomei in Annex A; the list in force is set by Commission Regulation (EU) 2026/1383, applicable since 29 June 2026. Cycas revoluta, grown worldwide in very large numbers from propagated stock (Hill, 2008), is traded mostly as nursery-grown plants. Before importing, selling or buying a rare Cycas, check its status on Species+ and ask for proof that the plant was propagated in cultivation. This general information does not replace the official texts. Species+ was consulted on 1 October 2026.

On the IUCN Red List, according to the statuses shown by The World List of Cycads and the species assessments, 73 of the 118 species are threatened: 20 Critically Endangered, 26 Endangered and 27 Vulnerable. Fifteen are Near Threatened, 23 Least Concern, including Cycas revoluta, and 7 have not been evaluated. The year of each assessment is given in the list of species below: most come from the reassessments published in 2022 and 2023, the others mainly from 2010; the year of the assessment of Cycas javana has not been verified. Hill (2008) cites two main threats in China: habitat destruction and the collection of wild plants for trade or for their uses. On Guam, the arrival of the scale insect Aulacaspis yasumatsui caused the collapse of the populations of Cycas micronesica (see Pests and diseases).

Growing Cycas

Most Cycas grown outside the tropics need very free-draining soil, plenty of light, summer warmth and a fairly dry winter; too much water is one of the commonest causes of failure. These rules apply above all to Cycas revoluta, for which sources are plentiful.

Outdoor and in-ground cultivation

  • Light: full sun to partial shade (UF/IFAS). In shade the leaves grow larger; in full sun the plant stays more compact. A plant brought out of a glasshouse or a house must be acclimatised gradually to the sun, otherwise its leaves scorch.
  • Soil: any soil, acid to alkaline, provided it drains well (UF/IFAS). The roots rot in overwatered or poorly drained soil (North Carolina State University Extension). A raised bed or rock garden reduces the risk. At the Jardin zoologique tropical in La Londe-les-Maures, in the south of France, the Cycas panzhihuaensis grow in a bank of crushed schist topped with volcanic gravel.
  • Watering: low needs; once established, Cycas revoluta tolerates drought well (UF/IFAS). To get new growth, however, it needs water in summer: in Roussillon, in southern France, a grower notes that his Cycas revoluta in full sun do not grow without summer watering. At the Jardin zoologique tropical, the Cycas panzhihuaensis, used to summer rain in their homeland, are watered once or twice a week in summer.
  • Feeding: Cycas are often short of magnesium and manganese; a palm fertiliser generally prevents these deficiencies (UF/IFAS).
  • Propagation: from seed, using fertilised seed, or by separating the offsets that sometimes form at the base of Cycas revoluta. Seeds move without a CITES permit thanks to annotation #4, except those of Cycas beddomei.

The Asian species are the easiest outside the tropics. The blue-leaved Australian Cycas, such as Cycas cairnsiana or Cycas couttsiana, lack summer heat in a European climate and rot easily, according to the site’s article on grafting them onto Cycas revoluta, a technique developed by Simon Lavaud, a French nurseryman specialising in cycads (Cycadales.eu), to grow them in pots under cover. Most tropical species tolerate no frost at all and are grown in a heated glasshouse or in a large pot brought indoors in winter; that is the norm in Britain and in all but the mildest parts of the United States.

Cycas
Cycas grown under glass in Denmark

Container cultivation

Yes, Cycas revoluta does well in a pot: the University of Florida recommends it as a container plant for patios. It is the safest option where winters are hard. The main points are:

  • Growing medium: very free-draining and largely mineral (volcanic gravel, grit, coarse sand), in a pot with drainage holes and no saucer of standing water.
  • Winter: in a pot the roots lack the thermal inertia of the ground and freeze sooner. A grower in Touraine (central France) reports on the Fous de palmiers forum that his young Cycas revoluta in a pot, forgotten outdoors during the cold spell of January 2010 at −9 °C (15.8 °F), was completely defoliated, then grew new leaves once brought back into the warm (message of March 2010). On Vancouver Island, in Canada, a grower reports on the UBC Botanical Garden forums that his Cycas panzhihuaensis in one-US-gallon pots (about 3.8 litres) came through −10 °C (14 °F) one night in January 2004 (message of May 2006). In Ravenna, Italy, potted Cycas sheltered from rain did not survive −7 °C (19.4 °F) (see Cold hardiness).
  • Shelter: a cold glasshouse, a bright conservatory or a frost-free room is enough. A grower in the Tarn (south-west France) reports on the same forum that his two potted Cycas revoluta, kept under a small glasshouse insulated with extruded polystyrene, saw −6 °C (21.2 °F) under cover in winter 2011–2012 while it was −12 °C (10.4 °F) outside: the larger plant showed no frost damage, the smaller had slightly damaged leaves (message of March 2012). At the Chelsea Physic Garden in London, the Cycas revoluta grows in a glasshouse, and the garden rates it “half hardy – unheated greenhouse / mild winter: 1 to −5 °C” (33.8 to 23 °F).
  • Watering: regular in summer, letting the mix dry out between waterings; almost none in winter in a cool room.
  • Moving outdoors in spring: gradually, first in partial shade, to avoid scorching leaves that grew under cover.

Cold hardiness

Three species are planted outdoors in temperate gardens: Cycas revoluta, Cycas panzhihuaensis and Cycas taitungensis. In all three, the foliage suffers before the trunk: depending on the species and the site, leaves are damaged between −5 and −10 °C (23 and 14 °F), but the trunk can regrow after −10 to −14 °C (14 to 6.8 °F) when the ground has frozen little. Published data on these thresholds remain scarce; most of what is known comes from growers’ reports.

Cycas revoluta: what the reference sources say

  • United States: the University of Florida extension service rates Cycas revoluta and Cycas taitungensis for USDA zones 8 to 11, with a limit of about −12 °C (10 °F) and leaves scorched between about −7 and −1 °C (in the 20s °F). North Carolina State University Extension, more cautious, gives zones 9a to 12b. The University of Florida recommends Cycas circinalis only for zones 10 and 11, that is, without significant frost.
  • United Kingdom: the Royal Horticultural Society rates Cycas revoluta H3, “hardy in coastal and relatively mild parts of the UK” (−5 to 1 °C; 23 to 33.8 °F), and advises growing it under glass, or in the open ground only in frost-free areas.

Cycas revoluta: growers’ reports from Europe

Most dated outdoor reports come from France, where Cycas revoluta has been planted out for decades. On the Mediterranean coast and in the south-west it survives most winters in the ground but regularly loses its leaves in cold winters. A grower in Roussillon sums up the experience of many enthusiasts on the Fous de palmiers forum: trunks regrow after −10 to −12 °C (14 to 10.4 °F) when the ground has frozen little or not at all, but the foliage “sulks” from −6 °C (21.2 °F), and the species is not reliable where −15 °C (5 °F) is reached. Further north and west, success depends on a dry, sheltered spot and winter protection. These Atlantic and continental results are the closest available guide for southern England and other mild, damp climates; no dated report is documented from Brittany or from mountain areas.

How to read the following reports. They are amateur observations published on the Fous de palmiers (France) and Tropicamente (Italy) forums and consulted in October 2026; they are indicative and do not amount to a general rule. Only complete reports and a few particularly useful incomplete ones are included. Where the place is given, the minimum recorded by the nearest Météo-France weather station is shown in brackets.

  • A grower in Bruguières (Haute-Garonne, near Toulouse) reports on the Fous de palmiers forum that his Cycas revoluta, planted out in 1980, about a metre across and until then unharmed by winters, did not survive the cold spell of January 1985: ten days of continuous frost, −17.5 °C (0.5 °F) at the lowest, daytime highs of −8 to −10 °C (17.6 to 14 °F) and an icy wind, without protection (messages of 2009 and 2012). The Météo-France station at Ondes, 9 km away, recorded −19.0 °C (−2.2 °F) on 9 January 1985, and Toulouse-Blagnac, 12 km away, −18.6 °C (−1.5 °F) on 16 January.
  • A grower in La Varenne-Saint-Hilaire (Val-de-Marne, south-east of Paris) reports on the Fous de palmiers forum that his four Cycas revoluta, in the ground for more than ten years and left unprotected, endured −12 °C (10.4 °F) in winter 2008–2009: only the largest, with a trunk over a metre tall and the most exposed, died (messages of January and December 2009). The Météo-France station at Saint-Maur, 2 km away, recorded −11.2 °C (11.8 °F) on 7 January 2009.
  • The same grower reports that a Cycas revoluta deliberately left unprotected had its foliage burnt in January 2010 at −7 °C (19.4 °F), while a neighbouring Cycas panzhihuaensis, also unprotected, showed only slight marks (message of January 2010; Saint-Maur recorded −8.8 °C, 16.2 °F, on 8 January 2010).
  • A grower in Nantes (Loire-Atlantique, western France) reports on the Fous de palmiers forum that his two Cycas revoluta, in the ground since 2004 and covered with horticultural fleece, were “badly damaged” in the cold spell of February 2012, with two nights at −9 °C (15.8 °F): the first time since they were planted (message of February 2012). The Météo-France station at Nantes-Bouguenais, 9 km away, recorded −8.4 °C (16.9 °F) on 12 February 2012.
  • A grower in Vienne (Isère, south of Lyon) reports on the Fous de palmiers forum that his orange-sized Cycas revoluta, in the ground for three years and protected only by a cloche, came through the cold spell of February 2012, with twelve days without thaw and −13 °C (8.6 °F) one night, without a mark on its foliage (message of May 2012). The Météo-France stations at Reventin, 7 km away, and Luzinay, 11 km away, recorded −11.8 °C (10.8 °F) and −12.9 °C (8.8 °F) on 5 February 2012.
  • A grower in the Ardèche (160 m above sea level) reports on the Fous de palmiers forum that his Cycas revoluta, in the ground for several years and unprotected, was completely defoliated in winter 2011–2012 by −14 °C (6.8 °F), and survived (message of February 2013).
  • A grower in Bordeaux (Gironde) reports on the Fous de palmiers forum that a Cycas revoluta planted in a street in Talence, which he passes regularly, came through the cold spell of February 2012 “without trouble”; he does not mention any protection (message of April 2013). The Météo-France station at Talence recorded −9.0 °C (15.8 °F) on 3 February 2012, and Bordeaux-Mérignac −8.8 °C (16.2 °F) on 9 February.
  • A grower in the Périgord Noir (Dordogne), in an Atlantic climate, reports on the Fous de palmiers forum that Cycas revoluta does not last long there without protection: it regularly loses its leaves and its trunk eventually rots in cold, wet winters; it succeeds, however, in sheltered spots of the Dordogne valley, such as La Roque-Gageac (message of January 2011). This report, without a date or a precise value, shows the part played by winter wet.
  • A grower in Ravenna (Emilia-Romagna, Italy) reports on the Tropicamente forum that his potted Cycas revoluta and Cycas panzhihuaensis, outdoors but sheltered from rain, did not survive the spell of December 2009, with snow, hoar frost and −7 °C (19.4 °F) (messages of December 2009 and September 2012). A grower in Numana (Marche, Italy) reports on the same forum that his Cycas revoluta, grown outdoors without shelter, had “not a scratch” after winter 2011–2012, with −5 °C (23 °F) at the lowest (message of September 2012).

Cycas panzhihuaensis, the most cold-tolerant

Yes, Cycas panzhihuaensis is reputed to be hardier than Cycas revoluta, and growers’ reports bear this out: its foliage holds up better, often intact where that of Cycas revoluta burns. Two Chinese laboratory studies confirm that it tolerates freezing better than Cycas bifida, thanks to greater stability of its membranes and photosynthesis (Zheng et al., 2021; Wu et al., 2023). No published source shows that it needs a dry winter: it has succeeded in the ground in the Nantes area, in western France. Its young leaves grown under glass are, however, fragile and snap in strong wind.

At the Jardin zoologique tropical in La Londe-les-Maures (Var, south-eastern France), several Cycas panzhihuaensis grown in full sun in very free-draining schist soil were exposed in January and February 2012 to −6 °C (21 °F) and snow, and “took this episode perfectly”; the only serious damage seen in fifteen years concerned leaves formed under glass (article published on the site in 2020). This Mediterranean experience may help growers in comparable climates, such as coastal California or southern Australia, without giving an exact equivalent for any particular place.

  • A grower in La Varenne-Saint-Hilaire (Val-de-Marne, south-east of Paris) reports on the Fous de palmiers forum that his Cycas panzhihuaensis, in the ground for its second winter and protected only by a light cover to keep it dry, came through winter 2008–2009 intact, with −12 °C (10.4 °F) at the lowest and three nights between −9 and −10 °C (15.8 and 14 °F); the same plant produced two flushes of leaves a year (messages of January and December 2009). The Saint-Maur station, 2 km away, recorded −11.2 °C (11.8 °F) on 7 January 2009.
  • A grower in Nantes (Loire-Atlantique) reports on the Fous de palmiers forum that his two young seed-grown Cycas panzhihuaensis, in the ground for two years, came through winter 2008–2009 at −8 °C (17.6 °F) without protection or damage (messages of June and December 2009; Nantes-Bouguenais recorded −8.8 °C, 16.2 °F, on 7 January 2009). The same grower reports that his large plant and his seedlings, under fleece, stayed intact in February 2012 with two nights at −9 °C (15.8 °F), while his Cycas revoluta were damaged (message of February 2012; −8.4 °C, 16.9 °F, at Nantes-Bouguenais on 12 February 2012).
  • A grower in the Béarn (Pyrénées-Atlantiques) reports on the Fous de palmiers forum that his Cycas panzhihuaensis, in the ground since 2009 and unprotected, was defoliated in the cold spell of February 2012 at −10 °C (14 °F) (messages of April 2010 and February 2012).
  • A grower in the Lot (south-west France) reports on the Fous de palmiers forum that his Cycas panzhihuaensis, in the ground without protection, saw about −11 to −12 °C (12.2 to 10.4 °F) in February 2012, while a thermometer 50 m away recorded −13 °C (8.6 °F): it is defoliated almost every winter but always regrows its leaves, and in six or seven years its trunk has grown from the size of a walnut to that of an apple (messages of April 2011 and May 2012).
  • A grower in Vienne (Isère) reports on the Fous de palmiers forum that the Cycas panzhihuaensis at the Lyon botanical garden did not survive its first winter, 2011–2012; he gives neither the temperature nor the growing conditions (message of May 2012). The Météo-France station at Lyon-Tête d’Or, in the park that houses the garden, recorded −11.0 °C (12.2 °F) on 5 February 2012.
  • A grower in Delémont (Jura, Switzerland) reports on the Fous de palmiers forum that his Cycas panzhihuaensis, protected by a polycarbonate roof and fleece, endured about −16 °C (3.2 °F) in winter 2014–2015: its leaves were scorched, but it produced three new leaves in May 2015 (message of May 2015).

Cycas taitungensis, as hardy as Cycas revoluta?

Not quite, according to growers’ reports: its foliage seems slightly more sensitive to cold than that of Cycas revoluta. General sources put the two at the same level: the University of Florida gives both species USDA zones 8 to 11, a limit of about −12 °C (10 °F) and leaves scorched between about −7 and −1 °C. Its growth, on the other hand, is faster, often with two flushes a year.

At the Jardin zoologique tropical in La Londe-les-Maures, the plants withstood −6 °C (21 °F) without damage in February 2012, when temperatures rose above freezing during the day, and have always grown fairly fast (article published on the site in 2020).

  • A grower in the Béarn reports on the Fous de palmiers forum that his Cycas taitungensis, in the ground since 2007 without protection, had its leaves damaged from −5 to −6 °C (23 to 21.2 °F) in winter 2008–2009, while his Cycas revoluta was unharmed; it stayed almost intact in 2009–2010 at −5 °C (23 °F), then was defoliated in February 2012 at −10 °C (14 °F). He judges it about 2 °C (3.6 °F) less cold-tolerant than Cycas revoluta (messages of 2009 to 2012).
  • A grower in La Varenne-Saint-Hilaire (Val-de-Marne) reports on the Fous de palmiers forum that his Cycas taitungensis, in the ground for more than two years, was completely defoliated in winter 2008–2009 at −12 °C (10.4 °F); the trunk survived but produced only a small crown eighteen months later (messages of April 2010 and January 2011; −11.2 °C, 11.8 °F, at Saint-Maur on 7 January 2009).
  • A grower in Roussillon (Pyrénées-Orientales) reports on the Fous de palmiers forum that his Cycas taitungensis, planted out eight years earlier, stayed intact in winter 2009–2010, with 27 nights of frost, −6 to −7 °C (21.2 to 19.4 °F) and 40 cm of snow, then in February 2012 with two nights at −7 °C (messages of 2010 to 2012).

Heat, drought, sun, wind and salt spray

  • Heat and drought: Cycas revoluta copes well with drought once established (UF/IFAS), but does not grow without water in summer. In Roussillon, Cycas revoluta planted in a very hot, south-facing corner turned yellow from late May, while those set almost in shade stayed in good condition. In the laboratory, a Chinese study showed that drought, well tolerated on its own by Cycas panzhihuaensis, worsens frost damage (Ling et al., 2024).
  • Sun: leaves formed in shade or under glass scorch if the plant is moved into full sun too quickly; in the Béarn, a newly planted Cycas panzhihuaensis had its leaf tips bleached by the sun in its first summer outdoors (message of April 2010).
  • Wind: in Roussillon, leaves of Cycas panzhihuaensis formed under glass snapped in winds of more than 100 km/h (62 mph), even in a sheltered garden (message of February 2012).
  • Excess water: the main cause of failure cited by growers, in the ground as in pots (see the Dordogne report).
  • Salt spray: no reliable data are documented for Cycas revoluta; the University of Florida considers Cycas circinalis to have low salt tolerance.

In cultivation in the UK, US and Australia

In short: in Britain, Cycas are glasshouse plants with the single documented exception of Cycas revoluta at Ventnor; in South Florida, coastal California and Australia, large collections of the genus are grown, many outdoors. The examples below come from the gardens’ own catalogues and publications. A species listed by a garden in the BGCI PlantSearch database (consulted in October 2026) shows that it has been declared there at some point, not that a living plant is there today.

  • Ventnor Botanic Garden (Isle of Wight): a male Cycas revoluta growing outdoors produced a cone in 2013 according to the garden’s Google Arts & Culture story (2012 in other accounts), and in summer 2019 a larger male cone and a female cone appeared together. The garden presents them as the first cones produced outdoors in the UK and attributes them to climate warming and heatwaves; it describes its microclimate as about 5 °C (9 °F) warmer than the rest of the country.
  • Other British gardens: the Cambridge University Botanic Garden catalogue lists Cycas pectinata (accession of 2017, wild origin), Cycas rumphii (1981, wild origin) and Cycas schumanniana (2017); the Chelsea Physic Garden grows Cycas revoluta in its glasshouse fernery. In 2010, a study at the Royal Botanic Garden Edinburgh found that several plants labelled Cycas circinalis were in fact Cycas rumphii, leaving a single true Cycas circinalis: a reminder that this name is often misapplied in cultivation. Kew, Edinburgh, Oxford, Glasgow and RHS Wisley all list several species of Cycas in BGCI PlantSearch.
  • United States: Montgomery Botanical Center (Coral Gables, Florida) holds one of the largest living collections of the genus; its catalogue listed 240 accessions of Cycas micronesica, 63 of Cycas revoluta and 34 of Cycas panzhihuaensis in October 2026, and in 2025 the garden reported that more than 1,800 seeds of Cycas cairnsiana, Cycas cupida, Cycas desolata and Cycas platyphylla had been collected in northern Queensland, half of them for its own collections. At the University of California Botanical Garden in Berkeley, Cycas multipinnata and Cycas micholitzii need the glasshouse (Plant Collections Network, 2015). At Lotusland (Montecito, California), one side of a path in the renovated cycad garden is lined with Cycas (newsletter, summer 2026).
  • Australia: the Royal Botanic Garden Sydney has 42 Cycas entries in its Garden Explorer (updated 1 October 2026), each with a bed number; the Australian Botanic Garden Mount Annan grows seven Australian species, including Cycas cupida and Cycas desolata. At Melbourne, the Royal Botanic Gardens Victoria census places Cycas revoluta, Cycas panzhihuaensis, Cycas szechuanensis and Cycas thouarsii in outdoor beds.

Pests and diseases

Two insects from Asia threaten cultivated Cycas around the world: a scale insect and a small butterfly. The other problems are mostly cultural: root rot in overwatered or poorly drained soil, mealybugs and mites (North Carolina State University Extension), magnesium and manganese deficiencies (UF/IFAS).

The cycad aulacaspis scale, Aulacaspis yasumatsui. This armoured scale attacks trunks, leaf bases, leaves, cones, seeds and even roots down to 60 cm (about 2 ft). According to the University of Florida, it can cover a Cycas revoluta within a few months and kill it within a year; it spreads over short distances on the wind and over long distances on transported plants. Treatment relies on repeated sprays of horticultural oil, possibly with an approved systemic insecticide. On Guam, where it arrived in 2003, a monitoring study showed that all seedlings of Cycas micronesica had been killed within 9 months and that 92 % of the plants were dead six years later (Marler and Lawrence, 2012). In Europe, the EPPO database records it as of 27 September 2026, with few occurrences, in Bulgaria, Croatia, Cyprus, Hungary, Poland, Slovenia, Turkey and the United Kingdom; in France it is recorded as absent, intercepted only.

The cycad blue, Chilades pandava. The caterpillars of this small blue butterfly, also called Luthrodes pandava, devour the young leaves of Cycas while they are growing and can kill seedlings. At Nong Nooch Tropical Botanical Garden in Thailand, damage varied by a factor of almost nine between species, among 85 species of Cycas grown together (Marler et al., 2012). The butterfly was first recorded in the Mediterranean basin in Egypt in 2014 (Fric et al., 2014), then in Lebanon in 2019; many observations have been posted on iNaturalist in Israel since at least 2024. No record from Europe is published for this page, and no European observation appeared on iNaturalist as of 1 October 2026. Its spread around the Mediterranean is a reason to watch new flushes closely.

Toxicity and precautions

Yes, Cycas are poisonous, and every part of the plant is; the seeds contain the most toxin. The main poison is cycasin (North Carolina State University Extension; ASPCA). In dogs, cats and horses, the ASPCA, the American animal poison control centre, reports vomiting, sometimes bloody diarrhoea, jaundice, clotting disorders, liver damage, liver failure and fatal cases; the Pet Poison Helpline adds nervous signs such as weakness, a wobbly gait or seizures. Dogs that chew seeds fallen on the ground are the most at risk.

In people, the University of Florida describes a powerful neurotoxin that can paralyse or kill when the plant is not properly prepared. On Guam, flour made from the seeds of Cycas micronesica was long suspected of causing a neurological disease that was very common among the Chamorro people, combining amyotrophic lateral sclerosis and parkinsonism with dementia. Cox and Sacks (2002) proposed that the toxins build up in flying foxes eaten locally; Steele and McGeer (2008) consider that this hypothesis does not meet the necessary criteria and that other causes must be considered. The link therefore remains debated.

Wear gloves when handling the seeds and their fleshy coat, pick up fallen seeds and keep plants and seeds out of reach of children and pets. The leaflet tips of Cycas revoluta are also sharp. If any part is swallowed, contact a poison centre, a doctor or a vet without delay.

Traditional uses

Cycas have served as famine food, at the cost of long work to remove their poison. According to the University of Florida, the inner bark of Cycas revoluta was eaten in Japan during famines. In Japan the expression sotetsu jigoku, “cycad hell”, refers to times when the people of the southern islands had nothing left to eat but cycads. The Okinawan daily Ryūkyū Shimpō reports that in 1945, on Hateruma Island, people cut the trunks, fermented them, extracted the starch and washed it repeatedly to remove the poison, and that this food of no nutritional value made the ravages of malaria worse. These preparations must not be copied. Today, the dried leaves of Cycas revoluta are used mainly in floristry, and the species is also grown as a bonsai in Japan (UF/IFAS).

Species of the genus Cycas

Here are the 118 species accepted by The World List of Cycads (version 2026.08.15), arranged by region. For each: author and year of publication, distribution, section where a published source states it, and IUCN status with the year of the assessment cited by The World List of Cycads or, where more recent or more precise, by the species assessment. Species shared between several regions are placed where most of their range lies. Species pages published under a former name are attached to the accepted species. Names without a link do not yet have an English page.

Japan, Taiwan and China

Twenty species, including the hardiest in the genus. Several Chinese species also grow in northern Vietnam.

  • Cycas revoluta Thunb. (1782): China (Fujian), Japan (Ryukyu Islands); the most widely grown species of the genus, the sago palm; Cycas miquelii is a synonym, a name also misapplied to other species; section Asiorientales; Least Concern (LC, 2023).
  • Cycas taitungensis C.F.Shen, K.D.Hill, C.H.Tsou & C.J.Chen (1994): Taiwan; very close to Cycas revoluta, with which POWO merges it (see Taxonomy); section Asiorientales; Endangered (EN, 2022).
  • Cycas panzhihuaensis L.Zhou & S.Y.Yang (1981): China (southern Sichuan, northern Yunnan); hot, dry valleys of the Jinsha; synonym: Cycas baguanheensis; section Panzhihuaenses; Vulnerable (VU, 2023).
  • Cycas szechuanensis W.C.Cheng & L.K.Fu (1975): China (Fujian, Guangdong); synonym: Cycas fairylakea; section Stangerioides; Critically Endangered (CR, 2024).
  • Cycas taiwaniana Carruth. (1893): southern China (Fujian and Guangdong according to The World List of Cycads, mostly in cultivation; wild populations on Hainan according to recent genetic studies); described from a plant said to come from Taiwan, but absent from the island; the Hainan plants described as Cycas hainanensis, Cycas lingshuiensis and Cycas shanyaensis are placed here; section Stangerioides; page under a former name: Cycas hainanensis; Endangered (EN, 2023).
  • Cycas changjiangensis N.Liu (1998): China (Hainan); formerly Cycas hainanensis subsp. changjiangensis; section Stangerioides; Endangered (EN, 2022).
  • Cycas guizhouensis K.M.Lan & R.F.Zou (1983): China (Guangxi, Guizhou, Yunnan); section Stangerioides; Vulnerable (VU, 2022).
  • Cycas chenii X.Gong & Wei Zhou (2015): China (Yunnan); Endangered (EN, 2023).
  • Cycas diannanensis Z.T.Guan & G.D.Tao (1995): China (central and eastern Yunnan, Red River valley), northern Vietnam (presence doubtful); synonyms Cycas parvula and Cycas multiovula; section Stangerioides; Endangered (EN, 2023).
  • Cycas hongheensis S.Y.Yang & S.L.Yang ex D.Yue Wang (1996): China (south-eastern Yunnan, Red River valley); section Indosinenses; Critically Endangered (CR, 2023).
  • Cycas multifrondis D.Yue Wang (1996): China (Yunnan); described from a plant cultivated at Xiamen Botanical Garden; Hill (2008) regarded it as a hybrid form between Cycas dolichophylla and Cycas bifida, The World List of Cycads accepts it as a species; Not Evaluated (NE).
  • Cycas tanqingii D.Yue Wang (1996): China (south-eastern Yunnan, Lüchun district), Vietnam (reported, without a specimen); section Stangerioides; Near Threatened (NT, 2023).
  • Cycas debaoensis Y.C.Zhong & C.J.Chen (1997): China (Guangxi); section Stangerioides; Critically Endangered (CR, 2023).
  • Cycas segmentifida D.Yue Wang & C.Y.Deng (1995): China (Guangxi, Guizhou, Yunnan), Vietnam (presence uncertain); section Stangerioides; Endangered (EN, 2023).
  • Cycas sexseminifera F.N.Wei (1996): China (Guangxi), Vietnam; section Stangerioides; Least Concern (LC, 2023).
  • Cycas balansae Warb. (1900): China (Guangxi), Vietnam; section Stangerioides; Endangered (EN, 2023).
  • Cycas bifida (Dyer) K.D.Hill (2004): China (Guangxi), Vietnam; section Stangerioides; Vulnerable (VU, 2022).
  • Cycas dolichophylla K.D.Hill, T.H.Nguyên & P.K.Lôc (2004): China (Guangxi, Yunnan), Laos (presence uncertain), Vietnam; section Stangerioides; Near Threatened (NT, 2023).
  • Cycas ferruginea F.N.Wei (1994): China (Guangxi), Vietnam; section Stangerioides; Near Threatened (NT, 2023).
  • Cycas multipinnata C.J.Chen & S.Y.Yang (1994): China (Yunnan), Vietnam; section Stangerioides; Critically Endangered (CR, 2023).

Indochina and Thailand

Twenty-five species, from Vietnam to Thailand, Laos, Cambodia and Myanmar, often on limestone hills or in dry forest.

  • Cycas aculeata K.D.Hill & T.H.Nguyên (2004): Vietnam; Endangered (EN, 2023).
  • Cycas brachycantha K.D.Hill, T.H.Nguyên & P.K.Lôc (2004): Vietnam; Vulnerable (VU, 2023).
  • Cycas chevalieri Leandri (1931): Vietnam; Vulnerable (VU, 2023).
  • Cycas collina K.D.Hill, T.H.Nguyên & P.K.Lôc (2004): north-western Vietnam and southern China (Yunnan), probably also Laos and Myanmar; section Stangerioides; Critically Endangered (CR, 2023).
  • Cycas condaoensis K.D.Hill & S.L.Yang (2004): Vietnam (Côn Đảo archipelago); Least Concern (LC, 2023).
  • Cycas elongata (Leandri) D.Yue Wang (1996): Vietnam; Endangered (EN, 2023).
  • Cycas fugax K.D.Hill, T.H.Nguyên & P.K.Lôc (2004): Vietnam; Critically Endangered (CR, 2023).
  • Cycas hoabinhensis P.K.Lôc & T.H.Nguyên (2004): Vietnam (north); Endangered (EN, 2023).
  • Cycas inermis Lour. (1793): Laos, Vietnam; Vulnerable (VU, 2022).
  • Cycas lindstromii S.L.Yang, K.D.Hill & T.H.Nguyên (1997): Vietnam (south coast, from Khanh Hoa to Ba Ria-Vung Tau); Endangered (EN, 2022).
  • Cycas micholitzii Dyer (1905): Laos, Vietnam; section Stangerioides, of which it is the type species; Vulnerable (VU, 2022).
  • Cycas pachypoda K.D.Hill (2004): southern Vietnam (Bình Thuận, Ninh Thuận); Critically Endangered (CR, 2023).
  • Cycas tropophylla K.D.Hill & P.K.Lôc (2004): Vietnam (Ha Long Bay and Cát Bà Island); Vulnerable (VU, 2023).
  • Cycas laotica Aver., T.H.Nguyên & S.K.Nguyên (2014): Laos (Khammouane province); Vulnerable (VU, 2023).
  • Cycas chamaoensis K.D.Hill (1999): Thailand; Critically Endangered (CR, 2022).
  • Cycas clivicola K.D.Hill (1999): Cambodia, Malaysia, Thailand, Vietnam; Least Concern (LC, 2023).
  • Cycas divyadarshanii Khuraijam & Rita Singh (2020): China (Yunnan), India (Manipur), Laos, Myanmar, Thailand, Vietnam; Not Evaluated (NE).
  • Cycas elephantipes A.Lindstr. & K.D.Hill (2003): Thailand; Endangered (EN, 2022).
  • Cycas macrocarpa Griff. (1854): Peninsular Malaysia, Thailand, Laos (presence to be confirmed, according to its discoverers); Vulnerable (VU, 2023).
  • Cycas nongnoochiae K.D.Hill (1999): Laos, Thailand; Vulnerable (VU, 2022).
  • Cycas petraea A.Lindstr. & K.D.Hill (2003): Thailand (Loei, Khon Kaen), Laos; Endangered (EN, 2023).
  • Cycas pranburiensis S.L.Yang, W.Tang, K.D.Hill & Vatch. (1999): Thailand; Critically Endangered (CR, 2023).
  • Cycas siamensis Miq. (1863): Myanmar, Cambodia, Laos, Thailand, Vietnam; section Indosinenses, of which it is the type species; Vulnerable (VU, 2023).
  • Cycas simplicipinna (Smitinand) K.D.Hill (1995): China (Yunnan, presence disputed), Laos, Myanmar (presence uncertain), Thailand, Vietnam; Near Threatened (NT, 2023).
  • Cycas tansachana K.D.Hill & S.L.Yang (1999): Thailand; Critically Endangered (CR, 2022).

India, Sri Lanka and the Andaman Islands

Thirteen species, including the type species of the genus. Several have been described since 2014 and their limits are still debated.

  • Cycas annaikalensis Rita Singh & P.Radha (2006): India (Kerala); Critically Endangered (CR, 2023).
  • Cycas beddomei Dyer (1883): India (Andhra Pradesh); the only species of the genus in CITES Appendix I, since 1987; Endangered (EN, 2022).
  • Cycas circinalis L. (1753): India (Andhra Pradesh, Karnataka, Kerala, Maharashtra, Tamil Nadu); type species of the genus, described by Linnaeus in 1753; section Cycas; a name very often misapplied in cultivation, mostly to Cycas thouarsii; Endangered (EN, 2023).
  • Cycas dharmrajii L.J.Singh (2017): India (Andaman Islands); not evaluated under this name (NE), included in Cycas sainathii by the Red List (VU, 2022).
  • Cycas indica A.Lindstr. & K.D.Hill (2007): India (Karnataka); Endangered (EN, 2023).
  • Cycas nathorstii J.Schust. (1932): India (Tamil Nadu), Sri Lanka; Vulnerable (VU, 2022).
  • Cycas nayagarhensis Rita Singh, P.Radha & Khuraijam (2015): India (Odisha); Critically Endangered (CR, 2022).
  • Cycas orixensis (Haines) Rita Singh & Khuraijam (2015): India (Odisha); Critically Endangered (CR, 2023).
  • Cycas pectinata Buch.-Ham. (1826): Bangladesh, Bhutan, India (Assam, Bihar, Meghalaya, Sikkim, West Bengal), Nepal; restricted by The World List of Cycads to the eastern Himalaya and Bangladesh; section Indosinenses; Vulnerable (VU, 2023).
  • Cycas pschannae R.C.Srivast. & L.J.Singh (2015): India (Andaman Islands); described from a plant cultivated at Howrah, near Kolkata, brought from the Andaman Islands; synonym: Cycas andamanica; not evaluated under this name (NE), included in Cycas sainathii by the Red List (VU, 2022).
  • Cycas seshachalamensis P.V.C.Rao, N.V.S.Prasad, P.M.Babu, K.Prassad & Prasanna (2016): India (Andhra Pradesh); Not Evaluated (NE).
  • Cycas sphaerica Roxb. (1832): India (Andhra Pradesh, Karnataka, Tamil Nadu); synonym: Cycas darshii; Endangered (EN, 2023).
  • Cycas zeylanica (J.Schust.) A.Lindstr. & K.D.Hill (2002): India (Andaman and Nicobar Islands), Sri Lanka (south coast); synonym: Cycas sainathii, which the Red List assesses separately (VU, 2022); Critically Endangered (CR, 2022).

Malaysia, Indonesia and the Philippines

Twenty species, twelve of them endemic to the Philippines.

  • Cycas cantafolia Jutta, K.L.Chew & Saw (2010): Malaysia; Vulnerable (VU, 2023).
  • Cycas edentata de Laub. (1998): Indonesia, Malaysia, Myanmar, Philippines, Singapore, Thailand, Vietnam; a very wide range, from Myanmar to the Philippines; Endangered (EN, 2023).
  • Cycas falcata K.D.Hill (1999): Indonesia; Vulnerable (VU, 2022).
  • Cycas glauca Hort. ex Miq. (1840): Timor-Leste, Indonesia (West Timor, Sumba); Critically Endangered (CR, 2023).
  • Cycas javana (Miq.) de Laub. ex D.Yue Wang (1996): Indonesia; Critically Endangered (CR, year not verified).
  • Cycas montana A.Lindstr. & K.D.Hill (2009): Indonesia; Least Concern (LC, 2023).
  • Cycas rumphii Miq. (1839): Australia (Ashmore Reef, Christmas Island), Indonesia, Papua New Guinea; Near Threatened (NT, 2023).
  • Cycas sundaica Miq. ex A.Lindstr. & K.D.Hill (2009): Indonesia; Least Concern (LC, 2023).
  • Cycas aenigma K.D.Hill & A.Lindstr. (2008): Philippines; Endangered (EN, 2023).
  • Cycas curranii (J.Schust.) K.D.Hill (1995): Philippines; section Wadeae; Critically Endangered (CR, 2023).
  • Cycas flabellata Agoo, Madulid & J.R.Callado (2019): Philippines; Not Evaluated (NE).
  • Cycas lacrimans A.Lindstr. & K.D.Hill (2008): Philippines; Endangered (EN, 2022).
  • Cycas mindanaensis Agoo, Madulid & J.R.Callado (2019): Philippines; Not Evaluated (NE).
  • Cycas nitida K.D.Hill & A.Lindstr. (2008): Philippines; Endangered (EN, 2023).
  • Cycas riuminiana Porte ex Regel (1863): Philippines; Endangered (EN, 2023).
  • Cycas sancti-lasallei Agoo & Madulid (2012): Philippines; Critically Endangered (CR, 2022).
  • Cycas saxatilis K.D.Hill & A.Lindstr. (2008): Philippines; section Wadeae; Vulnerable (VU, 2023).
  • Cycas vespertilio A.Lindstr. & K.D.Hill (2008): Philippines (Visayas and southern Luzon, also Mindoro and Marinduque); Vulnerable (VU, 2023).
  • Cycas wadei Merr. (1936): Philippines; section Wadeae; Critically Endangered (CR, 2022).
  • Cycas zambalensis Madulid & Agoo (2005): Philippines; Critically Endangered (CR, 2022).

Australia

Thirty-one species endemic to Australia, in Queensland, the Northern Territory and Western Australia. Three other species reach Australian territory from New Guinea or Indonesia.

  • Cycas angulata R.Br. (1810): Australia (Northern Territory, Queensland); Least Concern (LC, 2022).
  • Cycas arenicola K.D.Hill (1993): Australia (Northern Territory); Least Concern (LC, 2023).
  • Cycas armstrongii Miq. (1868): Australia (Northern Territory); Vulnerable (VU, 2022).
  • Cycas arnhemica K.D.Hill (1994): Australia (Northern Territory); Least Concern (LC, 2022).
  • Cycas badensis K.D.Hill (1996): Australia (Queensland, Badu and Moa Islands); Least Concern (LC, 2023).
  • Cycas basaltica C.A.Gardner (1923): Australia (Western Australia); Least Concern (LC, 2022).
  • Cycas brunnea K.D.Hill (1992): Australia (Queensland); Near Threatened (NT, 2022).
  • Cycas cairnsiana F.Muell. (1876): Australia (Queensland); Near Threatened (NT, 2023).
  • Cycas calcicola Maconochie (1978): Australia (Northern Territory: from Katherine to the Daly River basin and Litchfield National Park); Vulnerable (VU, 2023).
  • Cycas canalis K.D.Hill (1994): Australia (Northern Territory); Least Concern (LC, 2022).
  • Cycas candida K.D.Hill (2004): Australia (Queensland); Endangered (EN, 2022).
  • Cycas conferta Chirgwin (1993): Australia (Northern Territory); Vulnerable (VU, 2023).
  • Cycas couttsiana K.D.Hill (1992): Australia (Queensland); Near Threatened (NT, 2023).
  • Cycas cupida P.I.Forst. (2001): Australia (Queensland); Near Threatened (NT, 2023).
  • Cycas desolata P.I.Forst. (1995): Australia (Queensland); Near Threatened (NT, 2023).
  • Cycas distans P.I.Forst. & B.Gray (2017): Australia (Queensland); Endangered (EN, 2022).
  • Cycas furfuracea W.Fitzg. (1918): Australia (Western Australia); Least Concern (LC, 2022).
  • Cycas lane-poolei C.A.Gardner (1923): Australia (Western Australia, north-west Kimberley); Least Concern (LC, 2022).
  • Cycas maconochiei Chirgwin & K.D.Hill (1996): Australia (Northern Territory); three subspecies: lanata, maconochiei and viridis; Least Concern (LC, 2023).
  • Cycas media R.Br. (1810): Australia (eastern Queensland, from south of Mackay to the Cape York coast); three subspecies: banksii, ensata and media; Least Concern (LC, 2023).
  • Cycas megacarpa K.D.Hill (1992): Australia (central-eastern Queensland, from Mount Morgan to the Goomeri area); Vulnerable (VU, 2022).
  • Cycas ophiolitica K.D.Hill (1992): Australia (central-eastern Queensland, Marlborough and Rockhampton area); Vulnerable (VU, 2023).
  • Cycas orientis K.D.Hill (1994): Australia (Northern Territory, eastern Arnhem Land); Least Concern (LC, 2022).
  • Cycas platyphylla K.D.Hill (1992): Australia (Queensland); Endangered (EN, 2022).
  • Cycas pruinosa Maconochie (1978): Australia (Northern Territory, Western Australia); Least Concern (LC, 2022).
  • Cycas semota K.D.Hill (1996): Australia (Queensland); Vulnerable (VU, 2022).
  • Cycas silvestris K.D.Hill (1992): Australia (Queensland); Near Threatened (NT, 2010).
  • Cycas terryana P.I.Forst. (2011): Australia (central-eastern Queensland: Broadsound and Connors ranges); Vulnerable (VU, 2023).
  • Cycas tuckeri K.D.Hill (1996): Australia (Queensland: one population in the Coen district, Cape York Peninsula); Vulnerable (VU, 2023).
  • Cycas xipholepis K.D.Hill (1996): Australia (Queensland); Least Concern (LC, 2022).
  • Cycas yorkiana K.D.Hill (1996): Australia (Queensland); Near Threatened (NT, 2022).

New Guinea and the Pacific

Eight species, from New Guinea to the Solomon Islands, Micronesia, Fiji and Tonga.

  • Cycas apoa K.D.Hill (1994): Indonesia, Papua New Guinea; Least Concern (LC, 2023).
  • Cycas campestris K.D.Hill (1994): Papua New Guinea; Near Threatened (NT, 2022).
  • Cycas papuana F.Muell. (1876): southern New Guinea (Papua New Guinea, Western Province; Indonesia, Papua); Australia (Queensland, Prince of Wales Island) according to The World List of Cycads, presence to be confirmed; Least Concern (LC, 2023).
  • Cycas schumanniana Lauterb. (1900): Papua New Guinea (Madang, Morobe, Eastern Highlands); Indonesia according to Species+, not confirmed; Near Threatened (NT, 2023).
  • Cycas scratchleyana F.Muell. (1885): Papua New Guinea, Indonesia (Papua, Moluccas); Australia (one plant on Mer Island, Torres Strait, not accepted by Species+); Least Concern (LC, 2023).
  • Cycas bougainvilleana K.D.Hill (1994): Papua New Guinea, Solomon Islands; Near Threatened (NT, 2023).
  • Cycas micronesica K.D.Hill (1994): Guam, Micronesia, Northern Mariana Islands, Palau; devastated on Guam by the scale insect Aulacaspis yasumatsui (see Pests and diseases); Endangered (EN, 2022).
  • Cycas seemannii A.Braun (1876): Fiji, New Caledonia, Tonga, Vanuatu; Vulnerable (VU, 2022).

East Africa and Madagascar

A single species, the westernmost in the genus.

  • Cycas thouarsii R.Br. (1810): Comoros, Kenya, Madagascar, Tanzania (including Zanzibar); the only African species, named after the botanist Aubert du Petit-Thouars; Least Concern (LC, 2024).

Frequently asked questions

How many species of Cycas are there?

One hundred and eighteen, according to The World List of Cycads (version of 15 August 2026), plus six Australian subspecies. It is the largest cycad genus. The number has grown considerably since the 1990s: Hill counted about a hundred in 2008, and new species are still being described, mainly in India, the Philippines and Australia.

Is Cycas revoluta frost-hardy?

Up to a point. The foliage often burns from −6 to −9 °C (21.2 to 15.8 °F), but the trunk often regrows after −10 to −14 °C (14 to 6.8 °F) if the soil is dry and has frozen little. Losses occur in long, severe cold spells, as near Toulouse in January 1985 (−17.5 °C, 0.5 °F), and in wet soils. The University of Florida rates it for USDA zones 8 to 11 and the RHS rates it H3, hardy only in coastal and mild parts of the UK; elsewhere, winter protection or a pot brought into a frost-free place is safer.

Which is the hardiest Cycas?

Cycas panzhihuaensis, according to growers’ reports and two laboratory studies. In France its foliage stayed intact at −12 °C (10.4 °F) with almost no protection near Paris, and at −9 °C (15.8 °F) under fleece near Nantes, where that of Cycas revoluta was damaged. It is not indestructible, though: it is defoliated at around −10 °C (14 °F) without protection, and a plant at the Lyon botanical garden did not survive winter 2011–2012.

Is a Cycas a succulent or a palm?

Neither, strictly speaking. It is a gymnosperm, a plant with naked seeds, close to conifers in the way it reproduces, and not a palm, which is a flowering plant. It does share with succulents a good tolerance of drought once established (UF/IFAS).

How can you tell a male Cycas from a female?

Only when the plant reproduces. A male plant forms an upright, elongated cone at the centre of the crown; a female plant forms a rosette of hairy fertile leaves, with no cone, that carries the seeds along its edges, after which the stem resumes growth. You need a male and a female plant to obtain seed.

Is a Cycas dangerous to dogs and cats?

Yes, very. All parts are poisonous, the seeds above all, and poisoning can destroy the liver and cause death, according to the ASPCA. Pick up fallen seeds and contact a vet immediately if any part is eaten.

Do I need a CITES permit to buy a Cycas?

It depends on what you buy and where it comes from. Live plants of every species fall under CITES Appendix II (Annex B in the European Union): international trade in them requires documents, under the national rules of the United Kingdom, the United States, Australia or the EU. Seeds are exempt, except for Cycas beddomei, which is in Appendix I. A plant bought from a garden centre within your own country does not normally involve a CITES permit; buy nursery-grown plants, with proof of their origin.

Is Cycas taitungensis a species distinct from Cycas revoluta?

It depends on the source. The World List of Cycads and K. D. Hill accept it as a species, distinguished by its longer, flatter leaves; Kew’s World Checklist of Vascular Plants, the basis of POWO, lists it among the synonyms of Cycas revoluta. This site treats it as a separate species because of the differences seen in cultivation.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Linnaeus, C. (1753). Species Plantarum 2: 1188. Laurentius Salvius, Stockholm. [Publication of the genus and of Cycas circinalis; taken from The World List of Cycads.]
  • Hill, K.D. (2008). The genus Cycas (Cycadaceae) in China. Telopea 12(1): 71–118. https://doi.org/10.7751/telopea20085804 [Six sections, key and definition of sections Asiorientales, Panzhihuaenses, Stangerioides and Indosinenses, description of the genus, habitats, vernacular names and status of the Chinese species; peer-reviewed article.]
  • Lindström, A.J., Hill, K.D. & Stanberg, L.C. (2008). The genus Cycas (Cycadaceae) in the Philippines. Telopea 12(1): 119–145. https://doi.org/10.7751/telopea20085805 [Creation of section Wadeae, with Cycas wadei, Cycas curranii and Cycas saxatilis.]
  • Hill, K.D., Nguyen, H.T. & Loc, P.K. (2004). The genus Cycas (Cycadaceae) in Vietnam. The Botanical Review 70(2): 134–193. https://doi.org/10.1663/0006-8101(2004)070%5B0134:TGCCIV%5D2.0.CO;2 [Revision of the Vietnamese species; reference taken from Crossref.]
  • Lindström, A.J. & Hill, K.D. (2007). The genus Cycas (Cycadaceae) in India. Telopea 11(4): 463–488. https://doi.org/10.7751/telopea20075745 [Revision of the Indian species; reference taken from Crossref.]
  • Liu, J., Zhang, S., Nagalingum, N.S., Chiang, Y.-C., Lindstrom, A.J. & Gong, X. (2018). Phylogeny of the gymnosperm genus Cycas L. (Cycadaceae) as inferred from plastid and nuclear loci based on a large-scale sampling: evolutionary relationships and taxonomical implications. Molecular Phylogenetics and Evolution 127: 87–97. https://doi.org/10.1016/j.ympev.2018.05.019 [Thirteen lineages, six sections, Panzhihuaenses + Asiorientales in basal position; peer-reviewed article, consulted through its abstract.]
  • Feng, X.-Y., Wang, X.-H., Chiang, Y.-C., Jian, S.-G. & Gong, X. (2021). Species delimitation with distinct methods based on molecular data to elucidate species boundaries in the Cycas taiwaniana complex (Cycadaceae). Taxon 70(3): 477–491. https://doi.org/10.1002/tax.12457 [Two species recognised in the complex, Cycas hainanensis, Cycas lingshuiensis and Cycas changjiangensis included in Cycas taiwaniana; peer-reviewed article, consulted through its abstract.]
  • Zheng, Y., Liu, J., Feng, X. & Gong, X. (2017). The distribution, diversity, and conservation status of Cycas in China. Ecology and Evolution 7(9): 3212–3224. https://doi.org/10.1002/ece3.2910 [Treatment of Cycas multifrondis as a species by Chen, Yang and Li (2014); peer-reviewed article.]
  • Nagalingum, N.S., Marshall, C.R., Quental, T.B. et al. (2011). Recent synchronous radiation of a living fossil. Science 334: 796–799. https://doi.org/10.1126/science.1209926 [Living cycad species at most about 12 million years old; consulted through its abstract.]
  • Mankga, L.T., Yessoufou, K., Mugwena, T. & Chitakira, M. (2020). The cycad genus Cycas may have diversified from Indochina and occupied its current ranges through vicariance and dispersal events. Frontiers in Ecology and Evolution 8: 44. https://doi.org/10.3389/fevo.2020.00044 [Hypothesis of an Indochinese origin and role of the spongy endocarp.]
  • Yang, Y., Ding, Y., Peng, X. et al. (2026). Integrating habitat suitability and quality assessments to identify conservation priorities for Cycas panzhihuaensis. Plants 15: 670. https://doi.org/10.3390/plants15040670 [Habitat in hot, dry valleys, role of January temperature; consulted through its abstract.]
  • Zheng, Y., Yang, Y., Wang, M. et al. (2021). Differences in lipid homeostasis and membrane lipid unsaturation confer differential tolerance to low temperatures in two Cycas species. BMC Plant Biology 21: 377. https://doi.org/10.1186/s12870-021-03158-4 [Cycas panzhihuaensis more tolerant of freezing than Cycas bifida; consulted through its abstract.]
  • Wu, Y., Zhu, H., Ling, Z. et al. (2023). The metabolism of nonstructural carbohydrates, lipids, and energy in two Cycas species with differential tolerance to unexpected freezing stress. Frontiers in Plant Science 14: 1301560. https://doi.org/10.3389/fpls.2023.1301560 [Same conclusion for unexpected frosts; consulted through its abstract.]
  • Ling, Z., Lu, E., Peng, X., Yang, Y. & Zheng, Y. (2024). The physiochemical characteristics and glycerolipid profile of Cycas panzhihuaensis in response to individual and combined drought and freezing temperature stress. Plant Physiology and Biochemistry 214: 108907. https://doi.org/10.1016/j.plaphy.2024.108907 [Drought alone well tolerated but worsens frost damage; consulted through its abstract (Europe PMC).]
  • Marler, T.E. & Lawrence, J.H. (2012). Demography of Cycas micronesica on Guam following introduction of the armoured scale Aulacaspis yasumatsui. Journal of Tropical Ecology 28(3): 233–242. https://doi.org/10.1017/S0266467412000119 [92 % mortality six years after the scale’s arrival; consulted through its abstract.]
  • Marler, T.E., Lindström, A.J. & Terry, L.I. (2012). Chilades pandava damage among 85 Cycas species in a common garden setting. HortScience 47(12): 1832–1836. https://doi.org/10.21273/HORTSCI.47.12.1832 [Butterfly damage at Nong Nooch, Thailand; consulted through its abstract.]
  • Fric, Z., Dickinson, R., Fetouh, G., Larsen, T.B., Schön, W. & Wiemers, M. (2014). First record of the cycad blue, Chilades pandava, in Egypt — a new invasive butterfly species in the Mediterranean region and on the African continent. African Entomology 22(2): 315–319. https://doi.org/10.4001/003.022.0205 [First Mediterranean record, according to the title; reference checked on Crossref.]
  • Cox, P.A. & Sacks, O.W. (2002). Cycad neurotoxins, consumption of flying foxes, and ALS-PDC disease in Guam. Neurology 58(6): 956–959. https://doi.org/10.1212/WNL.58.6.956 [Hypothesis of toxin build-up in flying foxes; reference checked on Crossref.]
  • Steele, J.C. & McGeer, P.L. (2008). The ALS/PDC syndrome of Guam and the cycad hypothesis. Neurology 70(21): 1984–1990. https://doi.org/10.1212/01.wnl.0000312571.81091.26 [Critique of the cycad hypothesis; consulted through its abstract.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. [Etymology of species names; cited by The World List of Cycads.]
  • Clugston, J. (2010). Student project: data capture and taxonomic determination of Cycadales at the Royal Botanic Garden Edinburgh. Sibbaldia 8. https://journals.rbge.org.uk/rbgesib/article/download/134/124 [Re-identification of plants labelled Cycas circinalis; garden journal.]
  • Calonje, M., Stevenson, D.W. & Osborne, R. (2026). The World List of Cycads, version 2026.08.15. Montgomery Botanical Center, Coral Gables. https://doi.org/10.5281/zenodo.21958524 [Reference checklist: accepted species, synonyms, IUCN statuses.]