Cycas elongata

Cycas elongata is a cycad endemic to south-central Vietnam, recorded in five coastal provinces from Quang Ngai to Ninh Thuan. This member of the genus Cycas was first described in 1931 as a variety of Cycas pectinata, under the name Cycas pectinata var. elongata, and raised to species rank in 1996; it has also been placed in a genus Epicycas that is no longer recognised. Its name refers to the long terminal spine of its megasporophylls. The IUCN lists it as Endangered. It is one of the least documented cycads in cultivation: no growing data have been published.

Key facts about Cycas elongata

  • Accepted name: Cycas elongata (Leandri) D.Yue Wang (1996), 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 pectinata var. elongata Leandri (1931), the original name; Epicycas elongata (Leandri) S.L.Yang ex de Laub. (1998)
  • Family: Cycadaceae, order Cycadales
  • Common names: no English name could be traced to a reliable source (see Common names)
  • Natural range: south-central Vietnam (Quang Ngai, Binh Dinh, Phu Yen, Khanh Hoa, Ninh Thuan)
  • IUCN status: Endangered (EN), confirmed by the reassessment by J. D. Bösenberg and T. H. Nguyen published in 2023, which replaced that of H. T. Nguyen (2010, EN A2acd+4acd)
  • CITES and other protection: CITES Appendix II; Annex B in the European Union
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: not documented
  • Habit and adult size: a tree-like cycad with thin, smooth bark; dimensions not verified (see How to recognise)
  • In the UK, US and Australia: Royal Botanic Garden Sydney, five plants of wild origin (accession of 2006); no British or American record (see In cultivation in the UK, US and Australia)
  • Toxicity: not studied for the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas elongata

The sources that could be consulted give only two characters of Cycas elongata. Lindström and Hill (2007) and Hill (2008) note that its thin, smooth bark, without persistent leaf bases, is shared with Cycas pectinata and Cycas clivicola, and explain it by the rapid decay of the leaf bases in a humid climate. The name itself, according to Haynes (2022), refers to the elongated terminal spine of the megasporophylls, the fertile leaves of female plants.

The full description appears in the revision of the Cycas of Vietnam by Hill, Nguyen and Loc (2004, pages 174–176, figure 12) and in an article by Roy Osborne and Nguyen Tien Hiep in the journal Encephalartos (2002); neither text could be consulted.

Hybrids

No hybrid of Cycas elongata is known from the published sources.

Possible confusion

Its original name recalls that Cycas elongata was first attached to Cycas pectinata, a species that The World List of Cycads now restricts to the eastern Himalaya and north-eastern India. Within its range it grows alongside other cycads of southern Vietnam, such as Cycas pachypoda, with a strongly swollen trunk base, and Cycas lindstromii, with an underground trunk, both of which occur in Ninh Thuan Province. On the French forum Fous de palmiers, a traveller hesitated in 2010 between this species and Cycas inermis for cycads planted in the public gardens of Hanoi, without being able to decide.

Taxonomy

Cycas elongata is accepted by The World List of Cycads; the World Checklist of Vascular Plants (WCVP), on which POWO is based, also accepts it (consulted through GBIF on 31 October 2026). The French botanist J. Leandri described it in 1931 in the Flore générale de l’Indo-Chine (5(10): 1091) as a variety of Cycas pectinata. The revision of Hill, Nguyen and Loc (2004) designated a lectotype for the name, according to the abstract of their paper reproduced by The World List of Cycads; the lectotype is held at the Muséum national d’Histoire naturelle in Paris (P). In 1996, D. Y. Wang raised it to species rank in the book Cycads in China (page 51), under the spelling “elonga”, since corrected to elongata.

In 1998, de Laubenfels and Adema transferred it to a new genus, Epicycas, which current classifications do not accept: The World List of Cycads treats Epicycas as a synonym of Cycas. The detailed reasons for the 1996 change of rank and for the rejection of Epicycas could not be checked. For the reader, a label reading “Cycas pectinata var. elongata” or “Epicycas elongata” refers to this species.

The authority is written “(Leandri) D.Y.Yang” in Species+, which appears to be an error; this page follows The World List of Cycads. No published source gives the section of this species.

Etymology and history

The epithet comes from the Latin elongatus, “elongated”, after the long terminal spine of the megasporophylls (Haynes 2022, cited by The World List of Cycads). In China, plants about twenty years old are grown at the cycad conservation centre of Fairy Lake Botanical Garden, in Shenzhen, where they produce both male and female cones (Hu et al. 2016). The Royal Botanic Garden Sydney received its plants, of wild origin, in 2006. No information is documented on the history of the species in cultivation in Europe or the United States.

Common names

No English common name could be traced to a reliable source, and no Vietnamese name specific to the species could be checked. The Royal Botanic Garden Sydney labels the species simply “Cycad”.

In the wild

Cycas elongata is endemic to south-central Vietnam: The World List of Cycads records it in the provinces of Quang Ngai, Binh Dinh, Phu Yen, Khanh Hoa and Ninh Thuan. Its habitat, the altitude of its sites and its soils are not described.

Conservation status and regulation

Cycas elongata is listed as Endangered (EN) by the IUCN. The reassessment by J. D. Bösenberg and T. H. Nguyen, published in Red List version 2023-1, replaced the assessment by H. T. Nguyen (2010), which The World List of Cycads gives as EN A2acd+4acd, meaning a past and projected population decline; the EN category is confirmed by the IUCN data relayed by GBIF (consulted on 21 October 2026). The GBIF data give neither the criteria of the 2023 assessment nor the details of the threats.

Like the whole family Cycadaceae, it is listed in CITES Appendix II, with annotation #4 (CoP20 version, in force since 5 March 2026), which exempts seeds, pollen and seedlings or tissue cultures obtained in vitro in sterile containers; live plants still need permits. 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+ confirms this status and gives Vietnam as the only range state (consulted on 21 October 2026). This general information does not replace the official texts: check the rules in force before buying or exchanging plants, and buy only plants raised from seed in cultivation.

Growing Cycas elongata

In short: no growing data have been published. Only cultivation in two botanic gardens, in subtropical Shenzhen and in Sydney, is documented, without any description of methods.

Outdoor and in-ground cultivation

The Royal Botanic Garden Sydney lists its five plants in numbered garden beds, 82c and 89a; the catalogue does not say whether they are outdoors, although the numbered beds of this garden probably are, which would mean the species grows in the open in Sydney’s mild climate. The garden publishes no growing notes. At Fairy Lake Botanical Garden, in Shenzhen, plants about twenty years old produce cones (Hu et al. 2016). In other mild, frost-free climates an outdoor trial would be possible, but its needs for light, water and soil are not known.

Container cultivation

In the United Kingdom and other temperate regions it is a plant for a frost-free glasshouse or conservatory. No container growing report has been published.

In cultivation in the UK, US and Australia

In short: present in Sydney, apparently absent elsewhere. A garden listed in the BGCI PlantSearch database (consulted in October 2026) has declared the species at some point, which does not prove that a living plant is there today.

  • Australia: the online catalogue of the Royal Botanic Garden Sydney (updated on 1 October 2026) lists five plants of the 2006 accession S2006-0905, of wild provenance, three in bed 82c and two in bed 89a, under the name “Cycad”, with Vietnam as the native range. This is the only garden that lists the species in BGCI PlantSearch.
  • United States: no record in the online catalogues of Montgomery Botanical Center and Fairchild Tropical Botanic Garden or in the American lists in BGCI PlantSearch consulted in October 2026.
  • United Kingdom: no record.

No report from a private grower in the United Kingdom, the United States or Australia has been published.

Propagation

Like all Cycas, Cycas elongata is dioecious: a male and a female plant are needed for fertile seed. It is propagated from seed, as for other Cycas; no data specific to the species are documented. Seeds are exempt from CITES under annotation #4.

Pests and diseases

No data specific to Cycas elongata are documented. Like all Cycas, it is exposed to the Asian cycad scale, Aulacaspis yasumatsui, and to rot in waterlogged compost.

Cold hardiness

No cold-tolerance value has been published. No growing report exists on the French forum Fous de palmiers or the Italian forum Tropicamente, and the Jardin zoologique tropical at La Londe-les-Maures, in the south of France, has published no observation on the species. The only cultivation documented in a mild temperate climate is that of Sydney, where frost is rare and the plants are probably in the open; treat it as frost-tender.

Toxicity and precautions

No toxicity analysis specific to Cycas elongata 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. In dogs, cats and horses the ASPCA reports vomiting, sometimes bloody diarrhoea, jaundice, liver damage and fatal cases, and Pet Poison Helpline adds neurological signs. Wear gloves to handle the seeds and their fleshy coat, pick up fallen seeds and keep plants out of reach of children and pets; if any part is swallowed, contact a poison centre, a doctor or a vet straight away.

Traditional uses

No traditional use specific to Cycas elongata is documented.

Frequently asked questions

Is Cycas elongata a variety of Cycas pectinata?

Not any more. Described as a variety in 1931, it was raised to species rank in 1996, and The World List of Cycads accepts it as a species.

What does elongata mean?

“Elongated”, in Latin. The name refers to the long terminal spine of the fertile leaves of female plants.

Where does it grow?

Only in Vietnam, in five south-central provinces, from Quang Ngai to Ninh Thuan.

Is it endangered?

Yes. The IUCN lists it as Endangered (2023).

Can it be grown outdoors?

Possibly, in frost-free climates: the Royal Botanic Garden Sydney grows five plants in its garden beds, probably in the open. Elsewhere it should be kept frost-free, as nothing is known of its hardiness.

Is it poisonous?

It must be assumed so. It has not been studied, but all parts of Cycas are poisonous, especially the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Leandri, J. (1931). Cycadacées. In Lecomte, H. (ed.), Flore générale de l’Indo-Chine 5(10): 1091. [Description of Cycas pectinata var. elongata; reference taken from The World List of Cycads.]
  • Wang, D.Y. (1996). Taxonomy of Cycas in China. In Wang, F.X. & Liang, H.B. (eds), Cycads in China: 33–142 (combination p. 51). [Raised to species rank; reference taken from The World List of Cycads.]
  • de Laubenfels, D.J. & Adema, F. (1998). A taxonomic revision of the genera Cycas and Epicycas gen. nov. (Cycadaceae). Blumea 43(2): 351–400. [Combination Epicycas elongata; reference taken from The World List of Cycads.]
  • Osborne, R. & Nguyen, T.H. (2002). Focus on Cycas elongata. Encephalartos 72: 4–9. [Specialist society journal; reference taken from The World List of Cycads.]
  • Hill, K.D., Nguyen, H.T. & Loc, P.K. (2004). The genus Cycas (Cycadaceae) in Vietnam. The Botanical Review 70(2): 134–193. doi:10.1663/0006-8101(2004)070[0134:TGCCIV]2.0.CO;2 [Description, pages 174–176, figure 12; lectotypification.]
  • Lindström, A.J. & Hill, K.D. (2007). The genus Cycas (Cycadaceae) in India. Telopea 11(4): 463–488. doi:10.7751/telopea20075745 [Thin, smooth bark shared with Cycas pectinata.]
  • Hu, Y., Deng, T., Chen, L., Wu, H. & Zhang, S. (2016). Selection and validation of reference genes for qRT-PCR in Cycas elongata. PLoS ONE 11(4): e0154384. doi:10.1371/journal.pone.0154384 [Plants grown at Fairy Lake Botanical Garden.]
  • 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. doi:10.1002/ece3.2910 [Table of sections: hairless ovules in section Indosinenses.]
  • Nguyen, H.T. (2010). Cycas elongata. The IUCN Red List of Threatened Species 2010: e.T42054A10639875. doi:10.2305/IUCN.UK.2010-3.RLTS.T42054A10639875.en [Previous assessment, EN A2acd+4acd according to The World List of Cycads; reference checked on Crossref.]
  • Bösenberg, J.D. & Nguyen, T.H. (2023). Cycas elongata. The IUCN Red List of Threatened Species 2023: e.T42054A68900715. doi:10.2305/IUCN.UK.2023-1.RLTS.T42054A68900715.en [Current assessment, EN; reference checked on Crossref, category confirmed by GBIF.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. doi:10.11646/phytotaxa.550.1.1 [Etymology; cited by 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.]