Zamia oreillyi

Zamia oreillyi is a small cycad with an underground stem from the Caribbean coast of Honduras, known from a single site in the department of Atlántida, east of La Ceiba, at about 200 m in tropical moist forest. Described by the Honduran botanist Cyril Hardy Nelson Sutherland, this species of the genus Zamia is distinguished by its narrow leaflets and by a tiny male cone borne at the tip of a 16 cm peduncle. The IUCN rates it Critically Endangered (2022 assessment).

Key facts about Zamia oreillyi

  • Accepted name: Zamia oreillyi C.Nelson, accepted by The World List of Cycads (version 2026.08.15), by GBIF and by the World Checklist of Vascular Plants, on which POWO is based; POWO could not be consulted directly
  • Former names and synonyms: none
  • Family: Zamiaceae, order Cycadales
  • Common names: no English name; “camotillo” in Honduras (original description), a name used for all the Zamia of the country
  • Natural range: Honduras, department of Atlántida (Hacienda Agua Caliente, near Jutiapa), 200 m
  • IUCN status: Critically Endangered (CR), criteria A2acd+3cd+4acd; C2a(ii), 2022 assessment
  • CITES and other protection: CITES Appendix II (whole genus, since 1977; seeds exempt under annotation #4); Annex B in the European Union
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: lowland tropical moist forest; soil not documented
  • Habit and adult size: underground tuberous stem; the leaf described in the original description is 78 cm long, with 29 to 31 pairs of leaflets; one to three leaves in the wild
  • In the UK, US and Australia: Montgomery Botanical Center and the University of Hawaii at Hilo (US); no British or Australian record
  • Toxicity: no data specific to the species; the Zamia of Honduras have a reputation for being highly poisonous (see Toxicity and precautions)

How to recognise Zamia oreillyi

Zamia oreillyi is known only from a short description, published in the Honduran journal Ceiba, and its female cone has never been described. The original description gives:

  • Stem: an underground tuber.
  • Leaves: elliptic, 78.2 cm long; petiole 47 cm long, hairless, grooved, scattered with small spines 1 mm long; rachis narrow (2 mm), grooved, spineless, bearing 29 to 31 pairs of leaflets.
  • Leaflets: linear-lanceolate to oblong, narrowed at the base, gradually acuminate; margin regularly spiny in the upper half, with spines up to 3 mm long; the median leaflets measure 16 cm by only 1 cm, with no more than 20 veins.
  • Male cone: brown, cylindrical, only 2.9 cm long, on a hairless peduncle 15.9 cm long; scales 4 mm by 2 mm; pollen white.
  • Female cone: unknown.

The author points out two remarkable features: the contrast between this very small male cone and its long peduncle, and leaves that “recall the genus Chigua”, now merged into Zamia. The photograph that illustrates the leaf is captioned as a seedling in its natural habitat, so the leaf measurements may not reflect those of adult plants.

Hybrids

No hybrid, natural or raised in cultivation, has been documented.

Possible confusion

Honduras has four native Zamia, according to a 2016 overview by the herbarium of the Yucatán Scientific Research Centre (CICY); three have underground stems and live in the north of the country:

  • Zamia sandovalii, described in the same article and also from Atlántida: a cliff plant with leaflets 2 to 3 cm wide and 16 to 31 cm long, and reddish-brown male cones 11.2 cm long on a 16.7 cm peduncle;
  • Zamia standleyi, more widespread: six departments of northern Honduras and Izabal, in Guatemala, according to The World List of Cycads;
  • Zamia onan-reyesii, of the Merendón mountains, is told apart at once by its aerial trunk up to 2 m tall.

With no description of the female cone and no published key that includes the species, identification rests mainly on the narrow leaflets (1 cm) and the tiny male cone. The naturalist Jay Vannini distinguishes it from Zamia standleyi, a close relative, by its more numerous leaflets, whose edges overlap (Vannini, 2019).

Taxonomy

Zamia oreillyi is an accepted name according to The World List of Cycads, GBIF and the World Checklist of Vascular Plants, on which POWO is based (read on GBIF, version of 4 June 2026); POWO itself could not be consulted. It was published by Cyril Hardy Nelson Sutherland, a botanist at the National Autonomous University of Honduras, in an article describing two new Zamia from the Atlantic coast of the country, Zamia sandovalii and Zamia oreillyi.

The date and pagination of this article vary between sources. The issue on the journal’s website reads “Ceiba, 2005, volume 46(1-2): 55–58”; the version distributed by The Cycad Society reads “Ceiba, 2006, volume 46(1): 41–44”, with the description of the species on page 42; The World List of Cycads cites “Ceiba 46(1): 42” and dates the name to 2007; the World Checklist of Vascular Plants gives “Ceiba 46: 56 (2005 publ. 2007)”; and the 2008 article describing Zamia onan-reyesii writes “2005 [2007]”, meaning that the volume dated 2005 only appeared in 2007. It is the actual date of issue that counts in nomenclature. The name has never been placed in synonymy.

The World List of Cycads cites the 2009 revision of the Zamia of Mega-Mexico among its references; a 2011 molecular study could not sample it, for lack of material. The transcriptome phylogeny of Lindstrom and colleagues (2024) included a plant from Atlántida: species trees place it in a subclade (III-B) of the genus, while concatenated analyses group it with Zamia standleyi, Zamia sandovalii and Zamia purpurea of Mexico.

Etymology and history

The epithet honours Carlos Manuel O’Reilly, then a biology student at the National Autonomous University of Honduras and a volunteer at the TEFH herbarium, who took part in the expeditions during which the plant was found.

The type was collected on 8 April 2006 at Hacienda Agua Caliente, 2 km before the turn-off to Jutiapa, 32 km east of La Ceiba (Atlántida), in tropical moist forest at 200 m, by German Sandoval, Carlos O’Reilly and five other members of the expedition (no. 1157). It is kept in the herbarium of the National Autonomous University of Honduras (TEFH). Montgomery Botanical Center, in Florida, registered its first accession of the species in 2018, according to its online catalogue.

Common names

No English name is attested. The original description gives the local Spanish name “camotillo”, which applies to all the Zamia of Honduras. A 2016 overview also attributes the name “yuca de ratón” to Zamia oreillyi, whereas the original description gives it only for Zamia sandovalii.

In the wild

Zamia oreillyi is endemic to Honduras and known only from its type locality, near Jutiapa in the department of Atlántida, on the Caribbean coast, at about 200 m in tropical moist forest. A 2011 study places it in tropical evergreen forest, and Vannini (2019) describes a very localised species of the tropical rainforest of north-central Honduras. According to him, plants carry only one to three leaves in the wild, and their new leaf flushes are very handsome. Its soil, phenology and pollinator are not documented.

Conservation status and regulation

Zamia oreillyi is rated Critically Endangered (CR) by the IUCN, in an assessment by Anders Lindstrom and Cyril Hardy Nelson Sutherland published in 2022; an earlier assessment by Nelson had been published in 2010. The criteria used, A2acd+3cd+4acd and C2a(ii), denote, under the IUCN definitions, a population reduction of at least 80%, past, ongoing or expected, and a declining population of fewer than 250 mature individuals, at least 90% of them in a single subpopulation. The details of the threats are given on the Red List page, which could not be consulted.

Like all Zamia except Zamia restrepoi, which is in Appendix I, Zamia oreillyi is covered by the listing of the genus in CITES Appendix II, in force since 4 February 1977. Annotation #4 (the version adopted at CoP20, in force on 5 March 2026) exempts seeds, pollen, seedlings and tissue cultures obtained in vitro and transported in sterile containers, and cut flowers of artificially propagated plants; international trade in the plants themselves requires an export permit. In the European Union the species falls under Annex B of Regulation (EC) No 338/97, whose current list is set by Regulation (EU) 2026/1383, applicable since 29 June 2026. Species+, the official CITES database, names the species and confirms this status (checked on 3 October 2026).

This general information does not replace the official texts: check the regulations in force before buying or exchanging plants or seeds, ask the seller for proof of origin and prefer plants raised from cultivated seed.

Growing Zamia oreillyi

The botanic garden of the National Autonomous University of Honduras, in Tegucigalpa, holds one plant; a study published in 2026 reports that all the species in the collection except Ceratozamia hondurensis have produced cones there. No growing guidelines specific to the species have been published. Vannini (2019) notes that it is not widely cultivated, probably because planting material is scarce, but that it is probably a very good candidate for pot culture.

Simon Lavaud, of the French specialist nursery Cycadales.eu, lists Zamia oreillyi in his group of Zamia from Mexico, Guatemala, El Salvador and Honduras, of medium difficulty. For this group he recommends a free-draining, slightly alkaline or neutral compost; winter temperatures of 5 to 10 °C (41 to 50 °F) with daytime rises to 20 to 25 °C (68 to 77 °F); compost kept fairly dry, but not parched, during cool spells; and at least four to six months a year of summer temperatures (Lavaud, 2023). These are general recommendations for a group, not trials on the species, which comes from a humid lowland forest.

Outdoor and in-ground cultivation

Outdoors it is only conceivable in frost-free tropical climates with humid air, in the shade of trees and in free-draining soil, as in its forest habitat. None of the gardens that hold it says whether its plants are grown in the open.

Container cultivation

In temperate climates it is a plant for a warm glasshouse or conservatory, in partial shade, in a free-draining compost kept moist in the growing season. Its small size and few leaves suit a pot, as Vannini suggests.

In cultivation in the UK, US and Australia

In short: held by two American gardens; no British or Australian record.

  • United States: Montgomery Botanical Center (Coral Gables, Florida) lists four accession numbers in its online catalogue, from 2018, 2022, 2023 and 2024 (queried on 25 October 2026); BGCI also records it at the University of Hawaii at Hilo (queried on 25 October 2026). Fairchild Tropical Botanic Garden does not list it in its online catalogue.
  • United Kingdom: no record in BGCI.
  • Australia: no record in BGCI or in the online catalogue of the Royal Botanic Garden Sydney.

A BGCI declaration shows that a garden held the plant at some point, not that it is alive there today. In Europe, the Hortus Botanicus Amsterdam and the botanic garden of Lyon, in France, also declare it.

Propagation

The plant is dioecious: a male and a female plant are needed to obtain seed, and the female cone has not even been described. No germination data exist. Seeds are exempt from CITES under annotation #4; make sure they come from cultivated plants.

Pests and diseases

No pest or disease specific to the species has been documented. In cultivation, Zamia are chiefly at risk from root rot in cold, waterlogged compost and from scale insects.

Cold hardiness

No cold tolerance data exist for Zamia oreillyi. It is a plant of lowland tropical moist forest; nothing suggests that it tolerates frost.

Mediterranean and European experience

No growing result has been published in France, either in the ground or in a pot, and no dated frost episode concerns the species. For readers in Mediterranean-type climates such as coastal California or southern Australia, it remains a plant for frost-free conditions; in Europe, a heated glasshouse.

United Kingdom, United States and Australia

No cold record has been published outside Honduras. The gardens that hold it are in southern Florida and Hawaii, with tropical or subtropical climates. In the UK it needs a heated glasshouse all year.

Toxicity and precautions

No toxicity study specific to Zamia oreillyi has been published. The risk is, however, well documented in cycads: Zamia contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, a compound toxic to the liver and nervous system, and the ASPCA cites cycasin and BMAA, a neurotoxic amino acid, for Zamia furfuracea, which it lists as toxic to dogs, cats and horses; the seeds are the most dangerous part. In Honduras, the stems and roots of the “camotillos” have a reputation for being highly poisonous and, according to the 2016 overview, have been used to poison people and animals; this reputation concerns the country’s Zamia in general. In the absence of evidence to the contrary, treat the plant as poisonous: keep seeds and leaves out of reach of children and animals, and wear gloves to clean seeds. If any part is swallowed, contact a poison centre, a doctor or a vet straight away.

Traditional uses

No use specific to the species is documented. The reputation of the Honduran “camotillos” as poisons is described under Toxicity and precautions.

Frequently asked questions

Where does Zamia oreillyi grow?

Only in Honduras, at a single known site near Jutiapa (Atlántida), east of La Ceiba, at about 200 m in tropical moist forest.

How can it be recognised?

By its underground stem, its leaves with 29 to 31 pairs of narrow leaflets (1 cm wide), spiny in their upper half, and its tiny male cone, 2.9 cm long on a 16 cm peduncle.

Where does the name come from?

From Carlos Manuel O’Reilly, a student at the National Autonomous University of Honduras who took part in the expeditions that found it.

When was it described?

In volume 46 of the journal Ceiba, dated 2005 but issued in 2007 according to the sources; The World List of Cycads gives 2007.

Is it endangered?

Yes, severely. The IUCN rates it Critically Endangered (2022): fewer than 250 mature plants, almost all in a single population.

Is it grown in collections?

Rarely. Montgomery Botanical Center in Florida holds several accessions, and a few other botanic gardens in the United States and Europe declare it.

Is it hardy?

Almost certainly not. No cold data exist; it is a plant of lowland tropical forest.

Is it poisonous?

It must be assumed so. In Honduras, the Zamia (“camotillos”) have a reputation for being highly poisonous, and the cycads studied contain serious toxins.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Nelson Sutherland, C.H. (2005 [2007]). Dos plantas nuevas del género Zamia (Zamiaceae, Gymnospermae) en Honduras. Ceiba 46(1-2): 55–58. [Original description; full text read. The World List of Cycads cites “Ceiba 46(1): 42”, the pagination of the version distributed by The Cycad Society.]
  • Nicolalde-Morejón, F., González-Astorga, J., Vergara-Silva, F. & Vovides, A.P. (2011). Perspectivas sistemáticas de Zamia (Zamiaceae) en Megaméxico: de la taxonomía alfa a los códigos de barras genéticos. Revista Mexicana de Biodiversidad 82: 341–355. [Full text read.]
  • Rivera García, I.S. (2016). Los venenosos camotillos en Honduras: el género Zamia (Zamiaceae). Desde el Herbario CICY 8: 77–80. [Full text read.]
  • García, P.A., Banegas, S.C., Álvarez, M.N., Sanabria, D.L. & Rodríguez, M.J. (2026). Interacciones ecológicas y signos de estrés ambiental observadas en la familia Zamiaceae del Jardín Botánico de la Universidad Nacional Autónoma de Honduras. Revista Portal de la Ciencia 21: 65–76. https://doi.org/10.5377/pc.v1i21.23095 [Full text read.]
  • Lindstrom, A., Habib, S., Dong, S., Gong, Y., Liu, J., Calonje, M., Stevenson, D. & Zhang, S. (2024). Transcriptome sequencing data provide a solid base to understand the phylogenetic relationships, biogeography and reticulated evolution of the genus Zamia L. (Cycadales: Zamiaceae). Annals of Botany 134(5): 747–768. https://doi.org/10.1093/aob/mcae065 [Full text read on PubMed Central.]
  • Lindstrom, A. & Nelson Sutherland, C.H. (2022). Zamia oreillyi. The IUCN Red List of Threatened Species 2022: e.T178884A69832636. https://doi.org/10.2305/IUCN.UK.2022-1.RLTS.T178884A69832636.en [Red List assessment; reference given by The World List of Cycads and checked on Crossref; the Red List page could not be consulted.]
  • Nelson, C. (2010). Zamia oreillyi. The IUCN Red List of Threatened Species 2010: e.T178884A7634732. https://doi.org/10.2305/IUCN.UK.2010-3.RLTS.T178884A7634732.en [Earlier assessment; reference checked on Crossref, not consulted.]
  • Vannini, J. (2019). Central American and Panamanian cycads in field and greenhouse. Exotica Esoterica, 17 February 2019 (updated 2026). [Naturalist’s article; read.]
  • Lavaud, S. (2023). Comment cultiver les Zamia en climat tempéré. Cycadales.eu. [Growing advice for groups of species; read directly.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. https://doi.org/10.11646/phytotaxa.550.1.1 [Compendium 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. https://doi.org/10.5281/zenodo.21958524 [Reference checklist; consulted directly.]