Cycas circinalis

Cycas circinalis is a tree-like cycad endemic to southern India, where it grows mainly in the Western Ghats, in dry, scrubby hill woodland down to the coast. The first species described in the genus Cycas, and its type species, it is also the one whose name has been misapplied most often: for two centuries, tropical cycads from Asia, Africa and the Pacific were called “Cycas circinalis”, and most plants sold under this name today, in Europe as elsewhere, belong to other species, above all Cycas thouarsii from Madagascar and East Africa. The true Cycas circinalis, the queen sago of the horticultural literature, is almost absent from cultivation and is listed as Endangered by the IUCN, threatened by the harvesting of its leaves, pith and seeds.

Key facts about Cycas circinalis

  • Accepted name: Cycas circinalis L. (1753), 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)
  • Former names and synonyms: Cycas circinalis var. angustifolia Miq. (1840), Cycas wallichii Miq., Cycas undulata Desf. ex Gaudich. (1829), Cycas circinalis subsp. vera J.Schust. (1932); conversely, many names published under Cycas circinalis belong to other species (see Taxonomy)
  • Family: Cycadaceae, order Cycadales; type species of the genus and of section Cycas
  • Common names: queen sago (a horticultural name, often given to plants of other species); many Indian names (see Common names)
  • Natural range: southern India, Western Ghats (Kerala, Karnataka, Tamil Nadu, southern Maharashtra); The World List of Cycads adds Andhra Pradesh
  • IUCN status: Endangered (EN A2cd+4cd), 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: none for the species in the strict sense; plants sold under this name in the south of France damaged from 0 to −1 °C (32 to 30.2 °F), identity uncertain; the University of Florida gives USDA zones 10 and 11 for the queen sago (see Cold hardiness)
  • Light and soil: in the wild, seasonally dry hill woodland, rocky outcrops and the coast; in cultivation, strong light, free-draining soil, warmth
  • Habit and adult size: trunk up to 7 or 8 m, 12 to 43 cm across; leaves 1.5 to 2.7 m long
  • In the UK, US and Australia: one confirmed true plant at the Royal Botanic Garden Edinburgh in 2010; nine plants at the Royal Botanic Garden Sydney, two of them of wild Indian origin; one accession at Montgomery Botanical Center (Florida); the name is listed by dozens of gardens in BGCI PlantSearch, identity unchecked (see In cultivation in the UK, US and Australia)
  • Toxicity: no analysis specific to the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas circinalis

Cycas circinalis is a large cycad with flat leaves and long, broad leaflets, whose young leaves have a bluish sheen; it is recognised above all by its megasporophylls, which are not comb-like, and by its microsporophylls, which end in a long, tapering point (Lindstrom and Hill 2007).

The trunk reaches 7 m and 12 to 27 cm in diameter according to Lindstrom and Hill (2007), or 8 m and 27 to 43 cm according to de Laubenfels and Adema (1998); its bark is thick and corky. The leaves, bright green and semi-glossy, are 150 to 270 cm long and flat: the opposite leaflets are inserted at 180° on the rachis. Each leaf carries 54 to 110 leaflets. The petiole, 34 to 70 cm long, is spiny along 30 to 100 % of its length. The median leaflets are 22 to 36 cm long and 9 to 13 mm wide, with flat margins and a soft tip. The cataphylls are narrowly triangular and soft.

The male cones, ovoid to conical and pale brown to brown, are 24 to 48 cm long and 12 to 18 cm across; each microsporophyll ends in a prominent apical spine 20 to 39 mm long. The megasporophylls, 20 to 35 cm long, keep an orange down; they bear 4 to 14 hairless ovules and a lance-shaped blade 27 to 40 mm long, regularly toothed with 10 to 28 small, sharp spines 1 to 4 mm long. The elongated seeds, 30 to 39 mm by 20 to 24 mm, have pale yellow flesh and, according to Lindstrom and Hill (2007), no spongy inner layer.

In the wild the species sometimes sheds its leaves during extreme droughts (Lindstrom and Hill 2007). A field study in India (Raju and Rao 2011) describes bulbils that form on the trunks of male plants and can take root.

Hybrids

No natural or garden hybrid is documented for Cycas circinalis in the strict sense. The “circinalis hybrids” sometimes offered usually involve plants of other species sold under this name (see Possible confusion).

Possible confusion

“Cycas circinalis” in cultivation: a misapplied name

The short answer for growers: a plant bought as Cycas circinalis is very probably something else, most often Cycas thouarsii. In France, a specialist nurseryman stated in 2019 on the Fous de palmiers forum that the plants sold in garden centres as Cycas circinalis are Cycas thouarsii, and that the true Cycas circinalis is “virtually absent from cultivation”; in 2013 the same nurseryman had already written that what is sold under this name is, in most cases, Cycas thouarsii or Cycas rumphii. On the Italian forum Tropicamente, a grower made the same observation in 2009: the “circinalis” found in the trade are usually all thouarsii. In the United States, the University of Florida still describes the queen sago, a large tropical cycad with flat leaves grown in Florida gardens, under the name Cycas circinalis, without discussing its botanical identity.

The confusion goes back to Linnaeus himself. When he created the genus in 1753, he based Cycas circinalis on eight earlier works that actually described at least three species: only two refer to the Indian plant that now bears the name; the others correspond to Cycas revoluta, separated by Thunberg, and to Cycas rumphii, separated by Miquel in 1839 (Lindstrom and Hill 2007). Roxburgh then described under this name, in 1832, plants grown in Calcutta whose origin was wrongly given, which spread the false idea of a Cycas circinalis ranging from India to Indonesia (de Laubenfels and Adema 1998). Finally, in 1932, Schuster grouped a large part of the genus under Cycas circinalis as subspecies, varieties and forms.

The result, for Lindstrom and Hill (2007), is that the name is probably the one that appears most often in the literature, “without a single author having applied it entirely correctly”, and that almost all plants cultivated under it in fact belong to the Cycas rumphii complex. They list misapplications in Ceylon (Cycas nathorstii), Thailand, Malaysia (Cycas edentata), the Philippines, New Guinea and the western Pacific (Cycas seemannii, Cycas micronesica). De Laubenfels and Adema (1998) conclude that most records of Cycas circinalis of unknown origin should be set aside; they also note that studies on seed flotation attributed to this species were probably based on misidentified plants. Botanic gardens are no exception: in 2010, a study at the Royal Botanic Garden Edinburgh found that of four plants labelled Cycas circinalis, only one was the true species, the other three being renamed Cycas rumphii (Clugston 2010).

How to tell it from related species

  • Cycas thouarsii, from Madagascar and East Africa, the species most often sold under this name: much larger seeds (54 to 60 mm), with a spongy layer that makes them float, and microsporophylls ending in a short, hooked point (de Laubenfels and Adema 1998). The French nurseryman quoted above adds that its adult leaves are glossy, whereas those of Cycas circinalis are matt.
  • Cycas rumphii and its relatives from Indonesia and the Pacific: truncate microsporophylls with a very short point (about 5 mm), broader leaflets (14 to 18 mm) and ridged seeds that float (de Laubenfels and Adema 1998).
  • Cycas sphaerica, from the Eastern Ghats, long treated as part of Cycas circinalis (var. orixensis): more sharply tapering microsporophylls and longer teeth on the megasporophylls (de Laubenfels and Adema 1998; Lindstrom and Hill 2007).
  • Cycas nathorstii, from Sri Lanka and southern India: young leaves bright green, not bluish (Lindstrom and Hill 2007).
  • Cycas annaikalensis, a small population in the Annaikal hills near Palakkad, within the range of Cycas circinalis: distinct in its leaves, but its status still needs study (Lindstrom and Hill 2007).

The Edinburgh study adds a practical character: Cycas circinalis has a broad, undulating megasporophyll blade, less pronounced in Cycas rumphii and Cycas thouarsii (Clugston 2010). Without cones, a reliable identification is rarely possible.

Taxonomy

Linnaeus described Cycas circinalis in 1753 in Species Plantarum, as the only species of the new genus Cycas, with the note “Habitat in India”. As no specimen is linked to his description, plate 19 of the “Todda Panna” in Rheede’s Hortus Malabaricus, published in 1682, was designated as lectotype by Stevenson in 1993 (Lindstrom and Hill 2007). Cycas circinalis is also the type of the generic name.

Hill (1995), then Lindstrom and Hill (2007), restricted the name to an Indian species. The latter place some twenty combinations published under Cycas circinalis in other species: for example subsp. thouarsii and subsp. madagascariensis (= Cycas thouarsii), subsp. seemannii (= Cycas seemannii), subsp. papuana (= Cycas papuana), var. javana (= Cycas javana) and var. orixensis (= Cycas sphaerica). By contrast, var. angustifolia Miq. and its equivalent Cycas wallichii are synonyms of Cycas circinalis, as is Cycas undulata, described from a plant grown in Paris in 1820. De Laubenfels and Adema (1998) added Cycas squarrosa and Cycas squamosa, two nineteenth-century horticultural names.

The two revisions differ on the range: de Laubenfels and Adema (1998) recorded the species in Kerala and Sri Lanka, whereas Lindstrom and Hill (2007) refer the Sri Lankan plants to Cycas nathorstii. The World List of Cycads, which this site follows, accepts Cycas circinalis for India only.

Etymology and history

The epithet comes from the Latin circinalis, “coiled like a crozier”, referring to the coiled leaflets of the young leaves (Lindstrom and Hill 2007; Haynes 2022). Known for centuries in India, the plant entered Western writing with Rheede’s Hortus Malabaricus (1682), under the Malayalam name “Todda Panna”. Plants from southern India were grown in Europe by the early nineteenth century: according to Dyer, cited by de Laubenfels and Adema (1998), the horticultural form named Cycas squamosa had been introduced from Travancore in 1824.

Common names

In English the usual name is queen sago, used by the University of Florida and in the online catalogue of the Royal Botanic Garden Sydney; it is a horticultural name that, in practice, covers plants of other species sold under Cycas circinalis. The Orto Botanico di Palermo calls its large “Cycas circinalis” falso sagù, “false sago”, in Italian. In India, Lindstrom and Hill (2007) record among others jangli-madan-mast-ka-phul in Hindi, mundicalu in Kannada, madanagama and canningay in Tamil, kamkshi in Telugu and varaguna in Sanskrit; Species+ gives some of them.

In the wild

Cycas circinalis is endemic to the Western Ghats and neighbouring hills, in Kerala, Karnataka, Tamil Nadu and southern Maharashtra (Lindstrom and Hill 2007); The World List of Cycads adds Andhra Pradesh. It usually grows in fairly dense scrub woodland, dry for part of the year, on hills where many trees shed their leaves in the dry season, and it ranges from rocky outcrops down to the coast. Lindstrom and Hill (2007) describe it as an adaptable, locally abundant species, with large coastal populations in Kerala living alongside villages. De Laubenfels and Adema (1998) record it up to 1,070 m.

In the Nilgiri Biosphere Reserve, a study by the Keystone Foundation (Varghese and Ticktin) found heavily depleted populations: in those harvested for their leaves, 92 % of plants taller than 20 cm were cut and more than 90 % of their leaves removed; the populations harvested for their pith had no individuals taller than 50 cm left. Plants would take 15 to 20 years to reach reproductive age. Leaf production follows rainfall: one flush a year at the dry sites, leaves all year round after a main flush in May at the wettest site.

Pollination is debated. Raju and Rao (2011), who studied the species in India, consider it mainly wind-pollinated and note that the cones produce a little heat and scent, which in their view plays no role in pollination; they also describe a spongy layer that would make the seeds float, dispersed during the rainy season. Lindstrom and Hill (2007) and de Laubenfels and Adema (1998) state, on the contrary, that the seeds of Cycas circinalis have no spongy layer and do not float. The disagreement is unresolved; it may lie in the identity of the plants studied, but no source says so.

Conservation status and regulation

The IUCN lists Cycas circinalis as Endangered (EN A2cd+4cd), in the assessment by J. D. Bösenberg published in 2023 (category checked through GBIF and The World List of Cycads). The criteria point to past and future decline through habitat loss and exploitation. A previous assessment dates from 2010 (Varghese and colleagues); Donaldson (2003) had judged the data insufficient (DD).

The threats are well documented. In the Nilgiris, seeds and young leaves are eaten by indigenous communities, seeds are sold as a remedy in Kerala, the pith of the trunks and the male cones are collected by outside harvesters for traditional medicine markets, and mature leaves are cut in bulk in Tamil Nadu for the flower trade (Varghese and Ticktin, Keystone Foundation report). Lindstrom and Hill (2007) note that the habitat has been greatly reduced and degraded, but that good populations survive in national parks and forest reserves, and that people in Kerala do not cut the trunks as they do in Tamil Nadu and Andhra Pradesh.

Like every species in the genus except Cycas beddomei, it is listed in CITES Appendix II, where the whole family Cycadaceae has been included 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. The United Kingdom, the United States and Australia apply CITES through their own national legislation; in the European Union the species is in Annex B of Regulation (EC) No 338/97, whose annexes are set by Commission Regulation (EU) 2026/1383, applicable since 29 June 2026. Species+ gives India as the only range state (consulted on 19 October 2026). Check the rules in force before any purchase or exchange, and prefer plants raised from seed in cultivation.

Growing Cycas circinalis

In short: the true Cycas circinalis is almost absent from cultivation, and no growing advice specific to the species in the strict sense has been published. Its native habitat, tropical hills with a marked dry season, points to a warm-climate cycad that tolerates seasonal drought but not cold. The plants sold under this name, most often Cycas thouarsii, need the same care.

Outdoor and in-ground cultivation

The University of Florida’s factsheet on the queen sago gives the conditions under which the plant sold under this name is grown in Florida: USDA zones 10 and 11, sun or part shade, high drought tolerance once established, poor tolerance of salt in the soil, slow growth, and enough space for leaves 6 to 8 ft (about 1.8 to 2.4 m) long. It also notes that plants can be raised from seed or from divided suckers. By deduction, that limits it outdoors to frost-free or nearly frost-free gardens, such as southern Florida, the warmest parts of coastal California or tropical and subtropical Australia.

Around the Mediterranean the evidence concerns plants of uncertain identity. At the Orto Botanico di Palermo, in Sicily, “Cycas circinalis” planted outdoors in the nineteenth or early twentieth century are said to be the largest plants of this name grown outdoors in Europe. A grower on the west coast of Sicily, 1 km from the sea, reports on the Tropicamente forum that their “circinnalis” stayed outdoors in winter without problems (2009, 2013). These are exceptionally mild sites; elsewhere, the French and Italian reports given under Cold hardiness show damage at the first frost.

Container cultivation

In the United Kingdom, northern Europe and the cooler parts of the United States and Australia, it is a plant for a pot, brought into a bright, frost-free glasshouse or conservatory for the winter, in a very free-draining mix, watered regularly in summer and sparingly in winter, like the other tropical cycads. A grower in Ravenna (Emilia-Romagna, Italy) reports on the Tropicamente forum the loss of two plants sold under this name, one to rot and the other after two years of decline in a pot (2009). The Jardin zoologique tropical at La Londe-les-Maures, in the Var, has published no observation on the species.

In cultivation in the UK, US and Australia

In short: the name is everywhere in botanic garden lists, but the true species is rare, and few listings have been checked. A garden listed in the BGCI PlantSearch database (consulted in October 2026) has declared the name at some point, which proves neither that a living plant is there today nor that it is the true species.

  • United Kingdom: at the Royal Botanic Garden Edinburgh, the only British collection where the identity has been checked, a single true Cycas circinalis remained in 2010 after three plants labelled with the name were redetermined as Cycas rumphii (Clugston 2010); the garden’s species list places it in the Orchid and Cycad House. Glasgow Botanic Gardens, RHS Garden Wisley, the University of Bristol Botanic Garden, Treborth Botanic Garden and Durham University Botanic Garden also list the name in BGCI PlantSearch; their growing conditions and the identity of their plants are not stated.
  • United States: the online catalogue of Montgomery Botanical Center (Coral Gables, Florida) lists one accession, whose number points to 1995. Some forty American gardens list the name in BGCI PlantSearch, among them The Huntington, Ganna Walska Lotusland, San Diego Botanic Garden and the San Diego Zoo in California, the United States Botanic Garden in Washington, Longwood Gardens and The New York Botanical Garden; their plants have not been checked.
  • Australia: the online catalogue of the Royal Botanic Garden Sydney (updated on 1 October 2026) lists nine plants in bed 65b under the label “Queen Sago”, distribution India, two of which (accessions of 1993 and 1994) are of wild origin in India. By deduction, these wild-collected Indian plants are the most likely to be the true species, though no source has checked them against the recent revisions. Brisbane Botanic Gardens Mount Coot-tha, the Australian National Botanic Gardens in Canberra, Cairns Botanic Gardens, the Adelaide Botanic Garden and Kings Park in Perth list the name in BGCI PlantSearch.

No dated report from a grower in the United Kingdom, the United States or Australia has been published on English-language forums.

Propagation

Cycas circinalis is propagated from seed; a male and a female plant are needed. In the village nurseries of the Nilgiris, the first sowings germinated at only 20 to 30 %; burying the seeds in sand for two to three weeks before potting them raised the rate above 50 %, and a well-tended batch of 500 seeds exceeded 80 % germination, against about 60 % for a batch of 2,000 seeds in a less well-kept nursery (Varghese and Ticktin, Keystone Foundation report). The bulbils that form on the trunks of male plants can also take root (Raju and Rao 2011). Seeds are exempt from CITES under annotation #4.

Pests and diseases

No pest or disease specific to Cycas circinalis is documented in cultivation. Like all Cycas, it can be attacked by scale insects, including the Asian cycad scale, Aulacaspis yasumatsui, and it rots if the substrate stays wet in cool weather. For the queen sago, the University of Florida mentions scale as a minor problem, thrips that can disfigure the foliage and leaf-spot diseases that usually cause only minor damage.

Cold hardiness

No hardiness data exists for Cycas circinalis in the strict sense. The University of Florida limits the queen sago sold under this name to USDA zones 10 and 11, whose average annual minimums lie between −1.1 and 10 °C (30 and 50 °F): climates without significant frost.

The only cultivation reports concern plants sold under this name, whose identity is uncertain, and they come from the Mediterranean, an experience useful to readers in comparable climates such as California or southern Australia. A grower in Fuveau (Bouches-du-Rhône, France) reports on the Fous de palmiers forum that the leaves of a “Cycas circinalis” planted out the previous year were scorched at 0 °C (32 °F) in December 2019. A gardener in Carcassonne (Aude, France) reports on the Au jardin forum that their “Cycas circinalis” lost 99 % of their foliage at the first frost, at −1 °C (30.2 °F); the date could not be found. A grower in Lazio (Italy) reports on the Tropicamente forum, in December 2014, that the leaves of their “circinalis” were badly damaged two winters running and, once cut, were replaced by leaves a third as long. The French nurseryman quoted above sums up that the species sold under this name “tolerates only brief frosts; if it lasts, the foliage burns”. No result is known from the United Kingdom, where it should be overwintered frost-free under glass.

Toxicity and precautions

No toxicity analysis specific to Cycas circinalis in the strict sense is documented, but the risk is well documented in the genus: Cycas tissues, and the seeds above all, contain cycasin, which is converted during digestion into methylazoxymethanol, toxic to the liver and nervous system, along with a neurotoxic amino acid, BMAA. The ASPCA lists the sago palm (Cycas revoluta) among plants poisonous to dogs, cats and horses. In India the seeds are nevertheless eaten after preparation and sold as a remedy (Varghese and Ticktin, Keystone Foundation report); one of the Tamil names, canningay, is said to mean “hand convulsions”, perhaps a reference to its toxicity (Lindstrom and Hill 2007). Readers of older literature should note that “Cycas circinalis” from the western Pacific is Cycas micronesica, one of the misapplications listed by Lindstrom and Hill (2007). 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

In the Nilgiri Biosphere Reserve, indigenous communities eat the seeds and young leaves; in Kerala, the seeds are collected in large numbers and sold locally as a remedy; the pith of the trunk and the male cones supply traditional medicine markets, and the mature leaves the flower trade in Tamil Nadu (Varghese and Ticktin, Keystone Foundation report). The Hindi name jangli-madan-mast-ka-phul, “wild flower of sweet desire”, is said to allude to aphrodisiac virtues attributed to the plant (Lindstrom and Hill 2007).

Frequently asked questions

Is the Cycas circinalis from my garden centre the real thing?

Probably not. The true Cycas circinalis, from India, is almost absent from cultivation; plants sold under this name are most often Cycas thouarsii, or species of the Cycas rumphii complex.

How can the true Cycas circinalis be recognised?

Mainly by its reproductive organs: megasporophylls that are not comb-like, with small teeth, microsporophylls with a long tapering point, and seeds 3 to 4 cm long that do not float according to the main revisions. Its young leaves are bluish and its leaflets 9 to 13 mm wide.

Is the queen sago the same plant?

Not necessarily. Queen sago is the horticultural name attached to Cycas circinalis in Florida and Australia, but in the trade it covers plants of several species, especially Cycas thouarsii.

Where does it come from?

From southern India, mainly the Western Ghats (Kerala, Karnataka, Tamil Nadu, southern Maharashtra). It does not occur in Indonesia or Africa, contrary to many older sources.

Is it frost-hardy?

No. There is no data for the species in the strict sense, and plants sold under this name lose their foliage at 0 to −1 °C (32 to 30.2 °F). In the UK it must be overwintered frost-free under glass.

Is it endangered?

Yes. The IUCN lists it as Endangered (2023): its leaves, pith, cones and seeds are harvested in large quantities, and its habitat is shrinking.

Why has the name been misused so often?

Because Linnaeus based it on descriptions of several species, and Roxburgh, Miquel and Schuster then applied it to cycads from Asia, Africa and the Pacific. The revisions of 1995 to 2007 restricted it to India.

Is it poisonous?

It must be assumed so. There is no analysis for the species itself, but all the Cycas studied contain serious toxins, especially in the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Linnaeus, C. (1753). Species Plantarum 2: 1188. Laurentius Salvius, Stockholm. [Protologue; reference checked on The World List of Cycads.]
  • Rheede tot Drakestein, H.A. van (1682). Hortus Indicus Malabaricus 3, t. 19. Amsterdam. [Lectotype; cited after Lindstrom and Hill 2007.]
  • Hill, K.D. (1995). The genus Cycas (Cycadaceae) in the Indian region, with notes on the application and typification of the name Cycas circinalis L. Taxon 44(1): 23–31. doi:10.2307/1222674 [Restriction of the name to India; reference checked on Crossref.]
  • Laubenfels, D.J. de & Adema, F. (1998). A taxonomic revision of the genera Cycas and Epicycas gen. nov. (Cycadaceae). Blumea 43(2): 351–400. [History of the confusion, description, synonymy, non-floating seeds.]
  • Lindstrom, A.J. & Hill, K.D. (2007). The genus Cycas (Cycadaceae) in India. Telopea 11(4): 463–488. doi:10.7751/telopea20075745 [Description, lectotype, synonymy, table of misapplied combinations, distribution, conservation, vernacular names.]
  • Raju, A.J.S. & Rao, N.G. (2011). Taxonomic aspects and coning ecology of Cycas circinalis L. (Cycadales: Cycadaceae), a threatened species of India. Journal of Threatened Taxa 3(1): 1425–1431. doi:10.11609/JoTT.o2372.1425-31 [Pollination, bulbils, floating seeds according to the authors.]
  • Varghese, A. & Ticktin, T. (n.d., data 2006–2008). Conservation of the endemic overexploited cycad, Cycas circinalis L., in the Nilgiri Biosphere Reserve, South India. Final report, Keystone Foundation and The Cycad Society. [Harvesting, demography, germination.]
  • Clugston, J. (2010). Student project: data capture and taxonomic determination of Cycadales at the Royal Botanic Garden Edinburgh. Sibbaldia 8. [Redetermination of plants labelled Cycas circinalis.]
  • Bösenberg, J.D. (2023). Cycas circinalis. The IUCN Red List of Threatened Species 2023: e.T42089A2959396. doi:10.2305/IUCN.UK.2023-1.RLTS.T42089A2959396.en [Current assessment (EN); reference checked on Crossref.]
  • Varghese, A., Krishnamurthy, V., Garnesan, R. & Manu, K. (2010). Cycas circinalis. The IUCN Red List of Threatened Species 2010: e.T42089A10627275. doi:10.2305/IUCN.UK.2010-3.RLTS.T42089A10627275.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.]