Cycas nayagarhensis

Cycas nayagarhensis is a massive cycad of the sandstone hills of Nayagarh district, in the Indian state of Odisha, where only three small populations are known. This species of the genus Cycas was described in 2015 by Rita Singh, P. Radha and J.S. Khuraijam, in the same paper that raised Cycas orixensis to species rank. It stands out for its very thick trunk, broadened at the base, its large male cones and its bluish green leaves. The IUCN lists it as Critically Endangered.

Key facts about Cycas nayagarhensis

  • Accepted name: Cycas nayagarhensis Rita Singh, P.Radha & Khuraijam (2015), accepted by The World List of Cycads (version 2026.08.15) and by GBIF; POWO could not be consulted
  • Former names and synonyms: none
  • Family: Cycadaceae, order Cycadales
  • Common names: no English name attested; in Odisha, “aruguna”, “oruguna”, “orguna”, “oranga” and “odissimari”, names shared with Cycas orixensis
  • Natural range: India, Odisha, Nayagarh district (Gamein, Rukhi and Balram Hills)
  • IUCN status: Critically Endangered (CR B1ab(iii,v)), assessment by J.S. Khuraijam dated 2020 (Red List version 2022-1)
  • CITES and other protection: CITES Appendix II (seeds exempt under annotation #4); Annex B in the European Union; name not yet listed in Species+
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: in the wild, open rocky sandstone hills at 135 to 180 m; no cultivation data
  • Habit and adult size: trunk up to 5 m tall and 50 to 92 cm in diameter, single or branched; leaves 1.04 to 2.10 m long
  • In the UK, US and Australia: no garden record found
  • Toxicity: no data for the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas nayagarhensis

Cycas nayagarhensis is recognised by its enormous trunk, 50 to 92 cm across, wider at the base and narrowing towards the top, by its large ovoid male cones and by the scales of those cones, whose stout apical spine is only occasionally forked (Singh et al. 2015). As in Cycas orixensis, the megasporophylls (the fertile leaves of female plants) carry lateral spines and a long, spear-like apical spine.

The trunk, single or branched, reaches 5 m. On young plants the bark is thick, made of alternating bands of persistent leaf bases and cataphylls (the scale leaves that protect the growing point); on old trees it becomes smooth. The glossy, glaucous, bluish green leaves are 1.04 to 2.10 m long and carry 80 to 176 pairs of leaflets; the petiole, 28 to 47 cm long, bears 18 to 29 pairs of spines. The median leaflets, lanceolate, hairless and two-toned, measure 19 to 28 cm by 6 to 10 mm, with a midrib prominent on the underside.

The male cones, ovoid to almost conical and yellowish orange, are 18 to 43 cm long and 10 to 20 cm in diameter. The microsporophylls measure 4 to 5 cm by 2 to 2.5 cm and end in a stout, upturned spine 22 to 30 mm long, usually entire. The megasporophylls, 12 to 19 cm long and covered in yellowish orange hairs, carry 1 to 6 hairless ovules; their lanceolate blade, 7 to 8.5 cm long, bears 13 to 25 lateral spines 4 to 9 mm long on each side and an apical spine 30 to 46 mm long. The ovules are laterally compressed, spheroidal to broadly ellipsoidal, 33 to 38 mm long and 35 to 39 mm across, green when young and turning “mango yellow” when ripe, with a fibrous layer beneath the fleshy coat.

Hybrids

No hybrid is documented for this species.

Possible confusion

The likeliest confusion is with Cycas orixensis, the other cycad of Odisha. According to the key of Singh et al. (2015), Cycas nayagarhensis has a massive trunk (50 to 92 cm in diameter), large male cones (18 to 43 cm) and microsporophylls that are rarely forked, whereas Cycas orixensis has a slender trunk (12.5 to 32 cm), small male cones (11 to 21 cm) and microsporophylls that are very often forked; the ovules of Cycas nayagarhensis are also laterally compressed.

The authors separate it from Cycas circinalis by the forked tip of the microsporophylls, the occasionally forked lateral spines and the long, spear-like apical spine of the megasporophylls. They also note that its columnar trunk, of even diameter except for the broadened base, recalls that of Cycas swamyi, from Karnataka.

Taxonomy

Cycas nayagarhensis is a name accepted by The World List of Cycads and by GBIF; POWO could not be consulted. The species was described in 2015 in the Asian Journal of Conservation Biology, in the paper that raised Cycas circinalis var. orixensis to species rank as Cycas orixensis and created a new subsection, Orixenses, within section Cycas, for these two cycads of Odisha. The subsection is defined by the apical spine of the microsporophylls, simple or forked once or several times, and by the long lateral and apical spines of the megasporophylls.

No published molecular study placing these two species within the genus has been found: the subsection rests on morphological characters and on an analysis of morpho-anatomical similarity presented in the same paper.

Etymology and history

The epithet refers to Nayagarh district, in Odisha, the only place where the species grows naturally, in three populations (Singh et al. 2015; Haynes 2022).

The authors found these populations during several years of surveys in central Odisha: their more robust habit and different cones led them to separate them from Cycas orixensis. The type was collected in May 2009 by Rita Singh and J.S. Khuraijam (holotype no. 67409, held in the herbarium of GGS Indraprastha University in New Delhi, to be deposited at the Central National Herbarium in Howrah, CAL); further collections date from July 2010 and September 2011. No history of its introduction into cultivation is documented.

Common names

No English common name is attested. Singh et al. (2015) record the Odia names “aruguna”, “oruguna”, “orguna”, “oranga” and “odissimari”, the same as for Cycas orixensis: they cover the cycads of the region in general and do not distinguish the two species.

In the wild

Cycas nayagarhensis is known from only three populations in Nayagarh district: the Gamein, Rukhi and Balram Hills. It grows there on open, rocky sandstone hills between 135 and 180 m above sea level (Singh et al. 2015). Female cones start to appear in June and July, male cones from March to May. Pollination and seed dispersal are not documented.

Conservation status and regulation

The IUCN lists Cycas nayagarhensis as Critically Endangered (CR, criteria B1ab(iii,v)), in the assessment by J.S. Khuraijam dated 2020 and published in version 2022-1 of the Red List; the Red List data relayed by GBIF confirm this category (consulted on 21 October 2026). These criteria reflect a very small range, few populations and a continuing decline in habitat quality and in the number of mature plants. The authors of the species had already proposed this category in 2015 (under criterion B2), stressing the very small number of mature trees.

The threats they describe are the hacking of stems for religious and cultural rituals and land transformation linked to the expansion of the town of Nayagarh, which has caused a steep decline of the populations (Singh et al. 2015).

Like every species in the genus except Cycas beddomei, Cycas nayagarhensis is listed in CITES Appendix II, through the listing of the family Cycadaceae, 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 exempt, whereas international trade in the plants themselves requires an export permit. Australia, the United Kingdom and the United States 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, does not yet list this name, published in 2015 (searches of 3 and 12 October 2026): protection follows from the listing of the whole family, which covers every species, named or not.

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 origin and prefer plants raised from cultivated seed.

Growing Cycas nayagarhensis

In short: Cycas nayagarhensis is not documented in cultivation by any institution consulted, and no grower’s report was found; the French forum Fous de palmiers mentions it only to announce its description, in 2015. As a plant of sunny, rocky hills under a monsoon climate, it would presumably need warmth, full light and a very free-draining mineral mix; this is a deduction, not a published growing result.

Outdoor and in-ground cultivation

No planting result has been published anywhere. Only frost-free tropical and near-tropical climates can reasonably be considered for planting out.

Container cultivation

In temperate climates it would be a plant for a pot under heated glass. No container-growing report has been found: the Italian forum Tropicamente returns nothing for this species, and the Jardin zoologique tropical at La Londe-les-Maures, in the south of France, has published no observation on it.

In cultivation in the UK, US and Australia

No British, American or Australian garden record was found: the species does not appear in BGCI PlantSearch or in the online catalogue of Montgomery Botanical Center in Florida (searches of 21 October 2026), nor in the inventory of cycads in British, American and Australian gardens compiled for this site (19 October 2026). No report from an English-speaking grower could be read; PalmTalk and Dave’s Garden could not be consulted.

Propagation

The plant is dioecious: a male and a female plant are needed to obtain seed. Germination is cryptocotylar (the seed leaves stay inside the seed), as in other cycads, but no sowing data specific to the species have been published. Seeds are exempt from CITES under annotation #4. With only three populations, any collection from the wild bears directly on the survival of the species.

Pests and diseases

No pest or disease specific to the species is documented. Cycad scale insects, including the Asian cycad scale, Aulacaspis yasumatsui, can attack all cultivated species.

Cold hardiness

No cold-tolerance data exist for Cycas nayagarhensis. The hills of Nayagarh, at low altitude under a tropical monsoon climate, are frost-free, and nothing allows us to say that the plant tolerates frost.

Mediterranean experience

No growing result has been published in Europe, in the ground or in a pot, and no dated frost event concerns the species; the Jardin zoologique tropical in the Var has published nothing on it. Readers in comparable climates, such as California or southern Australia, have no European result to go on.

United Kingdom, United States and Australia

No cold reading or dated growing report was found, either on forums or from botanic gardens. No USDA zone can be given. In the UK, and in most of the United States and Australia outside the tropics, it would be a plant for heated glass.

Toxicity and precautions

No toxicity analysis specific to Cycas nayagarhensis has been 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. Until proven otherwise, 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 stems are hacked for religious and cultural rituals, to the point of threatening the populations (Singh et al. 2015). The rituals concerned are not described in the sources consulted.

Frequently asked questions

Where does Cycas nayagarhensis grow?

Only in Nayagarh district, in Odisha (India), on three sandstone hills: Gamein, Rukhi and Balram, between 135 and 180 m above sea level.

How can it be told from Cycas orixensis?

By the trunk and the cones: Cycas nayagarhensis has a massive trunk 50 to 92 cm across and large male cones whose scales are rarely forked; Cycas orixensis is slender, with small male cones whose scales are very often forked.

Where does its name come from?

From Nayagarh district, in Odisha, the only place where it grows.

Is it endangered?

Yes, critically. The IUCN lists it as Critically Endangered: there are only three populations, stems are hacked for rituals and the habitat is being eaten into by the growth of the town of Nayagarh.

Is it found in cultivation?

No cultivated plant is documented in the sources consulted, in India or in botanic gardens in the UK, the US or Australia.

Can it be grown outdoors in the UK?

Almost certainly not. No cold data exist and its native climate is frost-free; it would need heated glass.

Is it poisonous?

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

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Singh, R., Radha, P. & Khuraijam, J.S. (2015). A new species, a new combination and a new subsection of Cycas from Odisha, northern Eastern Ghats of India. Asian Journal of Conservation Biology 4(1): 3–14. [Original description (figs 4–6), subsection Orixenses, key to the Cycas of India; full text consulted.]
  • Khuraijam, J.S. (2022). Cycas nayagarhensis. The IUCN Red List of Threatened Species 2022: e.T103632199A103632290. doi:10.2305/IUCN.UK.2022-1.RLTS.T103632199A103632290.en [Red List assessment (dated 2020); reference found on The World List of Cycads and Crossref, category CR 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 given by The World List of Cycads; not consulted directly.]
  • Calonje, M., Stevenson, D.W. & Osborne, R. (2026). The World List of Cycads, version 2026.08.15. Montgomery Botanical Center, Coral Gables. doi:10.5281/zenodo.21958524 [Reference checklist; consulted directly.]