Cycas laotica

Cycas laotica is a cycad endemic to central Laos, known only from Khammouane province, where it grows on heavily eroded limestone hills between 150 and 400 m above sea level. This member of the genus Cycas was described only in 2014, in a survey of the gymnosperms of Laos, and it is one of the very few cycads known from that country alone. It is recognised by its trunk, swollen at the base into a partly underground caudex, and by its large, flat, glossy leaves carried on short, spineless petioles. The IUCN lists it as Vulnerable.

Key facts about Cycas laotica

  • Accepted name: Cycas laotica Aver., T.H.Nguyên & S.K.Nguyên (2014), accepted by The World List of Cycads (version 2026.08.15) and by GBIF; POWO could not be consulted directly
  • Former names and synonyms: none
  • Family: Cycadaceae, order Cycadales
  • Common names: no name attested, in English or any other language
  • Natural range: central Laos, Khammouane province (two subpopulations known when it was described)
  • IUCN status: Vulnerable (VU, criterion D2), assessment by T.H. Nguyen and L. Averyanov published in 2023; the authors of the species had proposed VU or EN in 2014
  • CITES and other protection: CITES Appendix II, like all Cycadaceae (seeds exempt under annotation #4); Annex B in the European Union
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: rocky outcrops, cliffs and thickets on limestone hills, often in full sun
  • Habit and adult size: trunk up to 2 m, rarely 3 m, 10 to 20 cm across, swollen at the base into an ovoid caudex up to 40 cm across; 30 to 45 leaves 0.6 to 1.4 m long
  • In the UK, US and Australia: one accession at Montgomery Botanical Center, Florida (2019)
  • Toxicity: no data for the species; treat it as poisonous, like all Cycas (see Toxicity and precautions)

How to recognise Cycas laotica

Two characters are enough to separate it from the other cycads of Laos: the trunk of adult plants, clearly swollen at the base into an ovoid caudex, and the petiole, which has no spines at all. This is the first choice in the key to the Cycas of Laos published with the original description. The rest of the description by Averyanov and colleagues (2014) reads as follows:

  • Trunk: plant stemless to tree-like, with a trunk up to 2 m tall (rarely 3 m) and 10 to 20 cm across, swollen into an ovoid underground caudex up to 40 cm across. The oldest plants reach 2 to 2.5 m, but some become fertile before forming an aerial trunk.
  • Leaves: 30 to 45 per crown, glossy, hairless, flat, 0.6 to 1.4 m long, with 60 to 100 pairs of leaflets.
  • Leaflets: linear and tapering to a point, with rolled margins; the basal leaflets are 8 to 10 cm long (sometimes 6 cm) and grade into spines, the median ones 12 to 15 cm.
  • Petiole: only 10 to 15 cm long, hairless, without spines.
  • Cataphylls (the scale leaves protecting the crown): narrowly triangular, pointed, 3 to 5 cm long, with orange-brown hairs, persistent.
  • Male cones: unknown when the species was described.
  • Megasporophylls (the fertile leaves of female plants): 14 to 16 cm long (sometimes 8 cm), with dull brown to yellowish-white felt, carrying 4 hairless ovules on a stalk 5 to 10 cm long; sterile blade an inverted triangle 5 to 6.5 cm long and wide, deeply comb-like, with 24 to 34 more or less rigid spines 1.5 to 2 cm long.
  • Seeds: yellow, globose, 1 to 1.5 cm according to the description.

The original description is not entirely consistent about the megasporophyll blade: the diagnosis mentions a distinct terminal spine, whereas the notes that follow list among the distinguishing features a truncate, comb-like tip without a prominent terminal spine. The sources consulted do not settle the point. The seed size, very small for a cycad, is given as published.

Hybrids

No hybrid, natural or cultivated, is documented.

Possible confusion

The authors of the description compare Cycas laotica with three species that also form a swollen trunk base: Cycas elephantipes and Cycas siamensis, from Thailand and neighbouring countries, and Cycas pachypoda, from Vietnam. It differs clearly from them in its large, straight, flat and glossy leaves, its very short, spineless petioles and the broad, inverted-triangular blade of its megasporophylls.

In Laos, the same survey records eight other Cycas: Cycas dolichophylla, Cycas inermis, Cycas macrocarpa, Cycas micholitzii, Cycas nongnoochiae, Cycas petraea, Cycas siamensis and Cycas simplicipinna. According to the key published in 2014, none of them has a swollen trunk base and all have a more or less spiny petiole; Cycas micholitzii is also recognised at once by its forked leaflets.

Taxonomy

Cycas laotica is a name accepted by The World List of Cycads and by GBIF; POWO could not be consulted directly. The species was published in 2014 by Leonid V. Averyanov, Nguyen Tien Hiep and Nguyen Sinh Khang in the Nordic Journal of Botany (32(6): 783), within a survey of the gymnosperms of Laos signed by ten Russian, Vietnamese and Lao authors. The same work recorded six other Cycas in Laos for the first time. IPNI writes the last author as “K.S.Nguyen” and The World List of Cycads as “S.K.Nguyên”: they are the same person.

The name has no synonym. None of the sources consulted places the species in a section of the genus: the authors simply compare it with the swollen-based cycads mentioned above, and its position in phylogenetic analyses has not been checked. For the reader, this means that the name is recent and stable, and that any plant offered under it should come with documented provenance.

Etymology and history

The epithet laotica refers to Laos, the country to which the species is endemic (Haynes 2022, as cited by The World List of Cycads). The type (Averyanov and colleagues LA-VN 234) was collected on 9 March 2013 near the village of Than En, in Mahaxay district (Khammouane province), at 300 m; the holotype is kept at the herbarium of the National University of Laos (NUOL), with isotypes in St Petersburg (LE), at the National Herbarium of Laos (NHOL) and at the Center for Plant Conservation in Hanoi. A second collection, made three days earlier about ten kilometres east of the town of Thakhek, at 150 m, is cited in the same description.

The discovery resulted from expeditions carried out in Laos between 2009 and 2013. In 2018 Averyanov and colleagues still cited Cycas laotica among the remarkable discoveries of the karst areas of Laos, regions they describe as largely unexplored botanically. No history of its introduction into cultivation is documented, although an accession entered the Montgomery Botanical Center collection in 2019 (see In cultivation in the UK, US and Australia).

Common names

No common name is recorded, in English or any other language. “Laos cycad” would be no more than a translation of the scientific name, not an attested name.

In the wild

Cycas laotica is known only from Khammouane province, in central Laos, where the original description cites two subpopulations, considered fairly large. It grows in dry broadleaved forest, primary or secondary, semi-deciduous or deciduous, in dense or open secondary thickets and on the rocky outcrops and cliffs of heavily eroded residual limestone hills, between 150 and 400 m, often in full sun. The authors describe it as a lithophyte, a plant growing on rock, and note that natural regeneration is normal. The World List of Cycads shows photographs taken in the same province in 2020 and 2024, and GBIF holds three observation records from Laos (consulted on 21 October 2026).

According to the description, pollination probably takes place from June to August and the seeds ripen in April and May. Its pollinators and seed dispersers are not documented.

Conservation status and regulation

Cycas laotica is listed as Vulnerable (VU) by the IUCN: this is the current category relayed by GBIF (consulted on 21 October 2026), and The World List of Cycads gives criterion D2, which applies to a very restricted area of occupancy or number of locations. The assessment, by Nguyen Tien Hiep and Leonid Averyanov, was published in version 2023-1 of the Red List (reference checked on Crossref); the Red List itself could not be consulted.

In 2014 the authors of the description noted that the species had not yet been assessed and proposed, provisionally, Vulnerable (VU) or Endangered (EN) under criteria B1 and B2ab(i–v): the two subpopulations are fairly large and regenerate well, but the range is very limited. Its habitats can easily be degraded or destroyed by fire, mining, road building, land development and excessive commercial collecting; in the authors’ view the species deserves full protection throughout its range.

Like every species in the genus except Cycas beddomei, Cycas laotica 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, has no separate page for the species: the name is recorded only with a reference to the genus Cycas, covered by the family listing (search of 12 October 2026). 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 laotica

In short: no growing experience has been published for Cycas laotica. In 2014 its authors wrote that they had no information on its cultivation, while judging it very promising as a small, palm-like ornamental tree for its handsome crown of leaves. Its natural habitat, rocky limestone hills at low altitude under a tropical climate with a dry season, suggests a plant for full sun or strong light, a very free-draining substrate and warmth; this is a deduction from its habitat, not a growing result.

Outdoor and in-ground cultivation

Only frost-free tropical and near-tropical climates can be considered. The limestone soil of its habitat suggests that an alkaline substrate would not harm it, but no trial confirms this. The Montgomery Botanical Center, in Coral Gables (Florida), whose collection is grown outdoors, has held one accession since 2019 (see below); no growing result has been published there.

Container cultivation

In temperate climates the safest choice is a heated glasshouse or a large pot brought in for the winter, with very sparse watering in the cool season, as for most tropical cycads. No report was found on the French forum Fous de palmiers (no result for this name on 13 October 2026) or on the Italian forum Tropicamente, and the Jardin zoologique tropical at La Londe-les-Maures, in the south of France, has published nothing on the species.

In cultivation in the UK, US and Australia

The online catalogue of Montgomery Botanical Center (Florida) lists one accession of Cycas laotica, number 20190172, which by the garden’s numbering dates from 2019 (search of 21 October 2026); BGCI PlantSearch also shows Montgomery as declaring the species, together with a European garden, the Jardí Botànic Marimurtra at Blanes, in Catalonia (search of 21 October 2026). A catalogue entry or a BGCI declaration does not show whether the plant is alive today or how it is doing. No British or Australian garden record was found, either in BGCI or in the inventory of cycads 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 fertile seed, and in cultivation pollination is usually done by hand. No germination data specific to the species have been published. Seeds are exempt from CITES under annotation #4; given the rarity of the species and the fragility of its habitat, accept only seed or plants of legal origin raised in cultivation.

Pests and diseases

No pest or disease specific to the species is documented. Cycad scales, including the Asian cycad scale, Aulacaspis yasumatsui, can attack all cultivated species, and standing water in cold weather exposes the trunk and roots to rot.

Cold hardiness

There are no cold-tolerance data for Cycas laotica. Its range, between 150 and 400 m in central Laos, has a tropical climate, and nothing allows us to say that the plant tolerates frost. No nursery consulted gives it a USDA hardiness zone.

Mediterranean experience

No growing result has been published in Europe, in the open ground or in a pot, and no dated frost event concerns the species. The Marimurtra garden in Catalonia declares the species in BGCI, but has published no observation on it.

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, keep it frost-free under glass.

Toxicity and precautions

No toxicity analysis specific to Cycas laotica has been found, 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) 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

No use of this species is documented in the sources consulted. CITES Appendix II does not ban trade but regulates it through export permits; given how small its range is, any collection from the wild should nevertheless be avoided.

Frequently asked questions

Where does the name laotica come from?

From Laos. The epithet recalls the country to which the species is endemic.

Where does Cycas laotica grow?

Only in central Laos, in Khammouane province, on limestone hills between 150 and 400 m, often in full sun.

How can it be recognised?

By its trunk, swollen at the base into an ovoid caudex, and its spineless petiole, a combination unique among the cycads of Laos. Its large, flat, glossy leaves, with 60 to 100 pairs of leaflets, complete the picture.

How big does it grow?

Not very. The trunk usually reaches 2 to 2.5 m in the oldest plants, exceptionally 3 m, and some plants become fertile before they have even formed an aerial trunk.

Is it endangered?

Yes. The IUCN lists it as Vulnerable because of its very restricted range; its habitats are exposed to fire, mining, road building and commercial collecting.

Can it be grown outdoors in the UK or in a Mediterranean climate?

Almost certainly not. No cold data or growing reports exist: it is a tropical plant, to be grown under heated glass or in a pot brought in for the winter.

Is it poisonous?

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

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Averyanov, L.V., Nguyen, T.H., Nguyen, S.K., Pham, T.V., Lamxay, V., Bounphanmy, S., Lorphengsy, S., Phan, L.K., Lanorsavanh, S. & Chantthavongsa, K. (2014). Gymnosperms of Laos. Nordic Journal of Botany 32(6): 765–805. doi:10.1111/njb.00498 [Original description of Cycas laotica (p. 783): description, collections, ecology, notes, proposed status; key to the Cycas of Laos. Primary source; full text read in the Early View version distributed by the Rufford Foundation.]
  • Averyanov, L.V., Nguyen, K.S. & Maisak, T.V. (2018). Xylacanthus laotica (Acanthaceae, Acanthoideae), a new genus and species from Laos. Turczaninowia 21(2): 101–110. doi:10.14258/turczaninowia.21.2.11 [Cites Cycas laotica among the discoveries of the karst areas of Laos; full text read.]
  • Nguyen, T.H. & Averyanov, L. (2023). Cycas laotica. The IUCN Red List of Threatened Species 2023-1: e.T66909904A66909936. doi:10.2305/IUCN.UK.2023-1.RLTS.T66909904A66909936.en [Current assessment (VU); reference checked on Crossref, category relayed by GBIF; text not consulted.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. doi:10.11646/phytotaxa.550.1.1 [Source of the etymology 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.]