Cycas annaikalensis

Cycas annaikalensis is a cycad of the Western Ghats of India, known from a single population of fewer than a hundred plants in the Annaikal hills, near Palakkad in Kerala, at about 940 m. Described in 2006 by Rita Singh and P. Radha, this species of the genus Cycas is distinguished from Cycas circinalis, which grows in the same region, by its smooth, steel-grey trunk and its leaves with more numerous leaflets. The IUCN lists it as Critically Endangered (CR).

Key facts about Cycas annaikalensis

  • Accepted name: Cycas annaikalensis Rita Singh & P.Radha (2006), accepted by The World List of Cycads (version 2026.08.15); POWO could not be consulted directly; sometimes misspelt “annakailensis”
  • Former names and synonyms: none; plants previously referred to Cycas circinalis (see Taxonomy)
  • Family: Cycadaceae, order Cycadales
  • Common names: no name attested, in English or any other language
  • Natural range: India, Kerala, Palakkad district, Annaikal hills (Western Ghats), at about 940 m
  • IUCN status: Critically Endangered (CR); first assessment by Rita Singh (2010, criteria B2ab(iii,v) and C2a(ii)), reassessment by J. D. Bösenberg published in Red List version 2023-1, still CR according to GBIF
  • CITES and other protection: CITES Appendix II (seeds exempt under annotation #4); Annex B in the European Union
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: understorey of tropical forest under a dense canopy, on steep slopes, in coarse black humus
  • Habit and adult size: trunk about 5 m tall; leaves 1 to 2.5 m long
  • In the UK, US and Australia: no botanic garden found in any of the three countries
  • Toxicity: no data specific to the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas annaikalensis

According to its authors, Cycas annaikalensis differs from Cycas circinalis and Cycas sphaerica by its smooth, steel-grey trunk without an armour of leaf bases, by its more numerous leaflets and their angle of insertion, and by its larger microsporophylls. The original description (Brittonia, 2006) could not be consulted; the description below is the one taken up by Lindström and Hill (2007):

  • Trunk: tree-like, about 5 m tall; bark smooth, steel grey, without persistent leaf bases or cataphylls.
  • Leaves: bright, semi-glossy green, 100 to 250 cm long, flat, with 200 to 240 leaflets; petiole 50 to 90 cm long, spiny along its whole length (spines 0.9 to 3 mm).
  • Median leaflets: 26 to 35 cm by 8 to 12 mm, inserted at 50 to 55°, with flat, not wavy margins; midrib raised above, flat beneath.
  • Cataphylls (the scales protecting the growing point): narrowly triangular, soft, finely silky or hairless.
  • Male cones: almost conical, orange-yellow before shedding pollen, 30 to 50 cm by 15 to 21 cm; microsporophylls 63 to 83 mm, with a long sterile part (38 to 47 mm) that narrows gradually into a spine.
  • Megasporophylls (the fertile leaves of female plants): 9 to 25 cm long, covered in dense, persistent rusty down, carrying 2 to 10 ovules; triangular blade 19 to 55 mm, regularly toothed (5 to 18 lateral spines of 5 to 8 mm), distinct terminal spine of 3 to 25 mm.
  • Seeds: globular, 38 to 49 mm by 35 to 43 mm, with a fleshy coat green then yellow, without a fibrous or spongy layer.

Hybrids

No natural or garden hybrid is documented.

Possible confusion

  • Cycas circinalis, endemic to the Western Ghats (Kerala, Karnataka, Tamil Nadu, southern Maharashtra), within whose range the Annaikal population lies: bluish young growth; according to the authors of Cycas annaikalensis, the latter differs by its smooth, steel-grey trunk, more numerous leaflets and larger microsporophylls;
  • Cycas sphaerica, from the Eastern Ghats: megasporophyll blade broader, with longer teeth than in Cycas circinalis;
  • Cycas indica, also from southern India: megasporophylls without a distinct terminal spine, according to the authors’ comparison.

Taxonomy

Cycas annaikalensis is accepted by The World List of Cycads; POWO could not be consulted directly. Rita Singh and P. Radha described it in 2006 in Brittonia (volume 58, pages 119 to 123), under the title “A new species of Cycas from the Malabar Coast, Western Ghats, India”. A second paper, by Rita Singh, P. Radha and Prabha Sharma, published in 2007 in the proceedings of the seventh international conference on cycad biology (Memoirs of the New York Botanical Garden 97, pages 542 to 556), discusses the limits of Cycas circinalis; it was not consulted.

Anders Lindström and Ken Hill, in their revision of the Cycas of India (Telopea, 2007), accepted the species with reservations. They noted that the population lies within the range of Cycas circinalis, that the description compared it only with the Cycas circinalis of Kerala and not with the whole range of that species, nor with Cycas sphaerica or Cycas indica, and that several distinguishing characters overlap with those of Cycas circinalis. In their view, the smooth trunk could reflect a wetter habitat in which the leaf bases rot away. They kept it on the strength of the differences in the leaves, while calling for further field study.

Etymology and history

The epithet refers to the Annaikal hills, the only known locality. In Malayalam, annai means “elephant” and kal “rock” (Lindström and Hill 2007).

Rita Singh recognised the plant as a distinct species during surveys carried out from 2001 to 2004. The type was collected in May 2003 by Rita Singh, P. Radha and Prabha Sharma in the Annaikal hills, Palakkad district, at 940 m; the holotype is kept at the Central National Herbarium in Kolkata (CAL), according to The World List of Cycads, and an isotype at Dehradun (DD), according to Lindström and Hill.

Common names

No common name is attested for this species, in English or in Malayalam, in the sources consulted.

In the wild

Cycas annaikalensis is known only from a population of fewer than 100 plants, over 100 to 250 m², in the Annaikal hills near Palakkad, at 940 m. The plants grow in the understorey, on steep slopes, in coarse black humus, under a dense canopy of tropical forest trees. The authors thought the species might also occur in the neighbouring reserved forests, and Lindström and Hill noted that the identity of other scattered populations in the area remained to be confirmed.

A project funded in 2017 by the Mohamed bin Zayed Species Conservation Fund and led by Peroth Balakrishnan (Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Thiruvananthapuram) reports that about 100 individuals survive in this single population, fewer than 20 of them reproductively mature, and that these adults do not cone often, so that annual seed production is critically low. Phenology and pollinators are not documented.

Conservation status and regulation

Cycas annaikalensis is listed as Critically Endangered (CR) by the IUCN. The first assessment, by Rita Singh (2010), used criteria B2ab(iii,v) and C2a(ii): a tiny area of occupancy, declining habitat and number of adults, and a very small population concentrated at a single site. A reassessment by John Donald Bösenberg was published in Red List version 2023-1 (reference checked on Crossref), and the IUCN data relayed by GBIF still give the CR category (consulted on 21 October 2026). In 2007, Lindström and Hill recommended Data Deficient (DD) instead, for lack of complete surveys. The Red List itself could not be consulted directly.

According to the 2017 project, the habitat is a heavily disturbed reserved forest outside the network of protected areas, affected by cattle grazing, hunting, unsustainable collection of forest produce and frequent fires. The plant itself suffers from collection of whole plants, leaves, cones and seeds by local people, traditional healers and plant sellers. The project planned a population survey, a search for other populations, a study of genetic diversity, the raising of young plants and awareness work with local people.

Like every species in the genus except Cycas beddomei, Cycas annaikalensis is listed in CITES Appendix II, where the family Cycadaceae has been included since 4 February 1977. The listing carries annotation #4 (CoP20 version, in force since 5 March 2026): seeds, pollen, seedlings or tissue cultures obtained in vitro and transported in sterile containers, and cut flowers of artificially propagated plants, are not subject to CITES, whereas international trade in the plants themselves requires an export permit. 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 in force are set by Commission Regulation (EU) 2026/1383, applicable since 29 June 2026. Species+, the official CITES database, names the species and confirms this status. This general information does not replace the official texts: check the rules in force before buying or exchanging plants, ask the seller for proof of provenance and prefer plants raised from seed in cultivation.

Growing Cycas annaikalensis

In short: no growing advice has been published for Cycas annaikalensis, and no growing report was found on the forums. Given its status, only plants raised in cultivation should circulate; no verifiable source reports it in the trade.

Outdoor and in-ground cultivation

Its habitat, humid forest understorey at middle altitude under a tropical monsoon climate, points to a plant for part shade in a frost-free climate. No outdoor cultivation has been documented anywhere outside its native site.

Container cultivation

In the United Kingdom and other temperate regions, it would be a plant for a heated glasshouse, in part shade. No growing trial has been published in Europe, and the Jardin zoologique tropical at La Londe-les-Maures, in the south of France, has published no observation on this species.

In cultivation in the UK, US and Australia

In short: no record found. The species does not appear in the online catalogues of the botanic gardens checked (Montgomery Botanical Center and Fairchild Tropical Botanic Garden in Florida, the Royal Botanic Garden Sydney, the Royal Botanic Gardens Victoria, Cambridge University Botanic Garden) or in the British, American and Australian lists of the BGCI PlantSearch database consulted in October 2026. No report from a private grower in these countries was found; PalmTalk and Dave’s Garden could not be consulted.

Propagation

The plant is dioecious: a male and a female plant are needed for seed. No germination data have been published; the 2017 project planned to raise young plants for conservation. Seeds are exempt from CITES under annotation #4, but their collection from the wild population is one of the threats facing the species.

Pests and diseases

No pest or disease specific to the species is documented. In cultivation, the Asian cycad scale, Aulacaspis yasumatsui, threatens cycads in general, but no attack has been reported on this species.

Cold hardiness

No cold-tolerance data exist for Cycas annaikalensis. The Annaikal hills lie in the tropics, and nothing suggests that the plant can take frost.

European experience

No cultivation result has been published in Europe, in the open ground or in a pot. A search of the French forum Fous de palmiers and the Italian forum Tropicamente found no report of cold tolerance for this species, and no dated frost episode concerns it. It is a plant for a warm glasshouse.

United Kingdom, United States and Australia

No cold reading and no dated growing report were found. Treat the plant as frost-tender; no USDA zone can be given without a documented trial.

Toxicity and precautions

No toxicity analysis specific to Cycas annaikalensis was found. The risk is, however, well documented in the genus: Cycas tissues, and the seeds above all, contain cycasin, which is converted during digestion into methylazoxymethanol, toxic to the liver and nervous system, along with a neurotoxic amino acid, BMAA. The ASPCA lists the sago palm (Cycas revoluta) as poisonous to dogs, cats and horses. In 2019 P. Radha and Rajasekhar Urla cloned a lectin gene from this species, a lectin being a protein that binds sugars (Journal of Plant Biochemistry and Biotechnology); this work does not concern its toxicity. In the absence of evidence to the contrary, treat the plant as poisonous: keep seeds and leaves out of reach of children and pets, and wear gloves to clean the seeds. If any part is swallowed, contact a poison centre, a doctor or a vet straight away.

Traditional uses

The 2017 project reports that traditional healers collect plants, leaves, cones and seeds, without specifying the uses. No use is described in the sources consulted.

Frequently asked questions

Where does Cycas annaikalensis grow?

Only in the Annaikal hills, near Palakkad, in Kerala (India), at about 940 m, in the understorey of tropical forest.

How many are left?

Very few: a single population of about 100 plants, fewer than 20 of them reproductive adults, according to a 2017 conservation project.

Is it just a form of Cycas circinalis?

Not according to current checklists, but the question has been raised. Lindström and Hill accepted it in 2007 with reservations, noting that several characters overlap with those of Cycas circinalis.

What does its name mean?

It comes from the Annaikal hills: in Malayalam, annai means “elephant” and kal “rock”.

What threatens it?

Collection of plants, leaves, cones and seeds, grazing, hunting and frequent fires, in a heavily disturbed reserved forest outside the protected-area network.

Can it be grown outdoors in the UK?

No, almost certainly not. No cold data exist; it is a tropical plant.

Is it poisonous?

It must be assumed so. No toxicity analysis specific to the species exists, but the Cycas studied contain dangerous toxins, especially in the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Singh, R. & Radha, P. (2006). A new species of Cycas from the Malabar Coast, Western Ghats, India. Brittonia 58(2): 119–123. doi:10.1663/0007-196X(2006)58[119:ANSOCF]2.0.CO;2 [Original description; not consulted (paywall), reference checked on Crossref.]
  • Singh, R., Radha, P. & Sharma, P. (2007). Cycas annaikalensis from the Western Ghats of India with a discussion on the specific limits of Cycas circinalis L. In Vovides, A.P., Stevenson, D.W. & Osborne, R. (eds), Proceedings of Cycad 2005. Memoirs of the New York Botanical Garden 97: 542–556. doi:10.21135/893274900.031 [Not consulted; reference checked on Crossref.]
  • Lindström, A.J. & Hill, K.D. (2007). The genus Cycas (Cycadaceae) in India. Telopea 11(4): 463–488. doi:10.7751/telopea20075745 [Description taken from the original, taxonomic discussion; full text consulted.]
  • Radha, P. & Urla, R. (2019). Cloning and characterization of mannose binding jacalin related lectin encoding gene from Indian Cycas (Cycas annaikalensis Singh and Radha). Journal of Plant Biochemistry and Biotechnology 29(2): 314–322. doi:10.1007/s13562-019-00513-3 [Reference checked on Crossref; not consulted.]
  • Singh, R. (2010). Cycas annaikalensis. The IUCN Red List of Threatened Species: e.T178883A7634502. [First Red List assessment; reference taken from The World List of Cycads and Crossref, Red List page not consulted (access blocked).]
  • Bösenberg, J.D. (2023). Cycas annaikalensis. The IUCN Red List of Threatened Species 2023: e.T178883A67334745. doi:10.2305/IUCN.UK.2023-1.RLTS.T178883A67334745.en [Reassessment; reference checked on Crossref, CR category relayed by GBIF; page not consulted (access blocked).]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. doi:10.11646/phytotaxa.550.1.1 [Source of the etymologies taken up by The World List of Cycads; not consulted directly.]
  • Calonje, M., Stevenson, D.W. & Osborne, R. (2026). The World List of Cycads, version 2026.08.15. Montgomery Botanical Center, Coral Gables. doi:10.5281/zenodo.21958524 [Reference checklist; consulted directly.]