Ceratozamia gigantea is a cycad of the mountain forests on karst of Tabasco, in south-eastern Mexico, known from a small area in the municipality of Macuspana. Described in 2024, it is one of the most recent species of the genus Ceratozamia, and takes its name from the large size of its trunk, leaves and cones. Its populations had first been referred to Ceratozamia subroseophylla, because the herbarium specimens lacked cones. It has not yet been assessed by the IUCN and is not known in cultivation outside Mexico.
Key facts about Ceratozamia gigantea
- Accepted name: Ceratozamia gigantea Mart.-Domínguez, Nic.-Mor., D.W.Stev. & Gonz.-Aguilar (2024), accepted by The World List of Cycads (version 2026.08.15) and by the World Checklist of Vascular Plants (WCVP, the database behind POWO, read via GBIF)
- Former names and synonyms: no synonym; plants first misidentified as Ceratozamia subroseophylla
- Family: Zamiaceae, order Cycadales
- Common names: none recorded
- Natural range: Mexico, Tabasco (municipality of Macuspana), mountain forests on karst; type locality at 185 m
- IUCN status: Not Evaluated (NE); a conservation status is proposed in the 2024 description
- CITES and other protection: CITES Appendix I (whole genus, since 1985); Annex A in the European Union, seeds included
- Documented hardiness: no data (see Cold hardiness)
- Light and soil: in the wild, forest on limestone karst; no growing advice published
- Habit and adult size: large trunk, leaves and cones according to its describers (see How to recognise)
- In the UK, US and Australia: no garden declares it
- Toxicity: no data specific to the species; treat it as poisonous, like all cycads (see Toxicity and precautions)
How to recognise Ceratozamia gigantea
According to its describers, Ceratozamia gigantea is recognised above all by its cones: the abstract of the article presents the reproductive structures as the primary means of identifying it. Its large dimensions (trunk, leaves and cones), which gave it its name, are the other feature they emphasise.
The detailed description, published in 2024 in the Kew Bulletin, is available only by subscription: the measurements of the trunk, leaves, leaflets, cones and seeds are therefore not given here. The article also contains an identification key to the related species and to all the species of Tabasco.
Hybrids
No natural or garden hybrid has been documented.
Possible confusion
The known confusion is the one that delayed its description: the specimens from Tabasco, which had no cones, had been referred to Ceratozamia subroseophylla, a species that The World List of Cycads places in Veracruz. The 2022 monograph of the genus, for instance, listed under Ceratozamia subroseophylla collections made in July 2021 in the municipality of Macuspana, at 185 to 190 m, and extended the range of that species to Tabasco. It was the cones, observed during fieldwork, that made it possible to separate the two species.
With its description, Tabasco has three species of Ceratozamia according to its authors; the characters that separate them are given in the key of the article. A plant from Tabasco without cones should therefore not be named with certainty.
Taxonomy
Ceratozamia gigantea is accepted by The World List of Cycads and by the WCVP, which records its publication in the Kew Bulletin 79, page 546 (2024), and places it in south-eastern Mexico. It was described in the Kew Bulletin (volume 79, pages 543 to 558), published online on 2 August 2024, by Lilí Martínez-Domínguez, Fernando Nicolalde-Morejón, Marlon Aramis González-Aguilar, Francisco Vergara-Silva and Dennis Stevenson; the name is attributed to four of them (Mart.-Domínguez, Nic.-Mor., D.W.Stev. & Gonz.-Aguilar).
The description is based on a study of phenology at a limestone karst site in Tabasco: the authors described the life span of the male and female cones and their changes in shape during development, then compared their collections with specimens of all the species of the genus. They also used DNA barcoding. In practice, a plant or specimen from Tabasco identified as Ceratozamia subroseophylla before 2024 may belong to this species.
Etymology and history
The epithet gigantea, a Latin adjective meaning “giant, large”, refers to the large size of the trunk, leaves and cones (original description, as quoted by The World List of Cycads).
The holotype was collected on 6 May 2023 by M.A. González-Aguilar and R. de la Cruz Raymundo in the municipality of Macuspana (Tabasco), at 185 m (collection 177); it is kept in the CIB herbarium, with an isotype in the National Herbarium of Mexico (MEXU).
Common names
No common name is known, in English or in Spanish.
In the wild
Ceratozamia gigantea is endemic to Tabasco, where it grows in mountain forests on limestone karst; the type locality lies at 185 m (about 610 ft). Its describers state that its range is restricted to a small geographical area, and that its discovery confirms the importance of limestone karst massifs as centres of speciation and endemism.
During their fieldwork, the authors caught pollinating insects on the female cones at the time when these were receptive, an observation rarely documented in Ceratozamia. The abstract of the article does not identify these insects.
Conservation status and regulation
Ceratozamia gigantea has not yet been assessed by the IUCN (Not Evaluated according to The World List of Cycads, version 2026.08.15). Its describers propose a conservation status in the 2024 article, after characterising its habitat; the abstract does not state the category chosen. Its very small range suggests that it is threatened, without any figures to show it.
Like the whole genus, it has been covered by CITES Appendix I since 1 August 1985, and by Annex A of Regulation (EC) No 338/97 in the European Union (annexes now set by Regulation (EU) 2026/1383, applicable since 29 June 2026), seeds included. Species+ does not yet name this species, described after the CITES standard reference, but the listing covers the whole genus (Ceratozamia spp.) and therefore includes it (checked on 30 October 2026).
This general information does not replace the official texts: check the regulations in force before buying or exchanging plants, ask the seller for proof of origin, and prefer plants raised from cultivated seed.
Growing Ceratozamia gigantea
No growing advice specific to Ceratozamia gigantea has been published, and no grower has reported on it: described in 2024, the species is not known in cultivation outside Mexico. Its habitat, low-altitude tropical forest on limestone, suggests a warm, humid glasshouse, partial shade and a free-draining substrate. These pointers are deduced from the natural habitat and have not been confirmed by published trials. Its large size would make it a bulky plant in cultivation.
Outdoor and in-ground cultivation
No outdoor planting has been documented. Only frost-free tropical gardens, with shade and well-drained, limy soil, would match its habitat; this is inferred, not tested.
Container cultivation
No container-growing report exists. Elsewhere it would be a plant for a large heated glasshouse, in a deep, free-draining mix with limestone grit, kept warm all year.
In cultivation in the UK, US and Australia
No garden in the United Kingdom, the United States or Australia declares Ceratozamia gigantea to BGCI PlantSearch, and the name does not appear in the living collection of Montgomery Botanical Center (both checked on 30 October 2026). Plants from Tabasco grown before 2024 may carry the name Ceratozamia subroseophylla.
Propagation
No data specific to the species. Like all Ceratozamia, it has separate male and female plants; it would be propagated from fresh seed after pollination, handling the seeds with gloves.
Pests and diseases
No pest or disease specific to the species has been documented.
Cold hardiness
No cold-tolerance data exist for Ceratozamia gigantea. It is a species of low-altitude tropical forest (185 m at the type locality): nothing suggests that it can take frost.
Mediterranean and European experience
No growing result has been published in France or Italy, in the ground or in a pot, and the Jardin zoologique tropical in La Londe-les-Maures (Var, on the French Riviera) has published no observation of it. In Mediterranean-type climates such as California or southern Australia, it should be kept frost-free.
United Kingdom, United States and Australia
No cold record and no commercial hardiness rating have been published. In the UK it would need a heated glasshouse.
Toxicity and precautions
No toxicity data exist for the species or the genus. The risk is documented in other cycads: their seeds and leaves contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, a compound harmful to the liver and nervous system. Dogs, livestock and people can be seriously poisoned. Treat the plant as poisonous, keep seeds and leaves out of reach of children and animals, and if any part is swallowed, call a poison centre, a doctor or a vet straight away.
Traditional uses
No use has been documented.
Frequently asked questions
Why is it called gigantea?
Because its trunk, leaves and cones are large: gigantea means “giant” in Latin.
Where does it grow?
Only in Tabasco, Mexico, in the mountain forests on karst of the municipality of Macuspana. Its range is very small.
How does it differ from Ceratozamia subroseophylla?
They are two distinct species. The plants from Tabasco had been referred to Ceratozamia subroseophylla because the specimens had no cones; studying the cones showed that they belonged to another species.
Is it endangered?
Probably, but the IUCN has not assessed it yet. Its range is limited to a small area, and its describers proposed a conservation status that the abstract of their article does not state.
Is it cold-hardy?
No, as far as anyone knows. It is a species of low-altitude tropical forest, to be grown frost-free in a warm glasshouse.
Can it be bought?
Not without documents. It is covered by the listing of the whole genus in CITES Appendix I and Annex A of the EU regulation, seeds included, and no commercial offer has been documented.
Further reading on Succulentes
- How to Grow Cycads from Seed: Germination, Seedling Care and Propagation Setup
- Watering Cycads: Common Mistakes and How to Avoid Them
- Is Sago Palm Toxic to Dogs, Cats & Children? What to Know
Sources
Reference sites
- The World List of Cycads (version 2026.08.15), Ceratozamia gigantea: https://cycadlist.org/scientific_name/1063 — authors, publication, type, range, IUCN status (NE), etymology. Checklist of the IUCN Cycad Specialist Group, reliable; reread on 30 October 2026.
- World Checklist of Vascular Plants (WCVP, Royal Botanic Gardens, Kew), via GBIF, Ceratozamia gigantea: https://api.gbif.org/v1/species/262420477 — accepted name, Kew Bulletin 79: 546 (2024), south-eastern Mexico. Kew data, the basis of POWO, distributed by GBIF; consulted on 30 October 2026.
- Kew Bulletin, Ceratozamia gigantea (Zamiaceae), a new species of cycad, endemic to the mountain karst forests of Tabasco, Mexico (2024): https://doi.org/10.1007/s12225-024-10209-0 — abstract: former confusion with Ceratozamia subroseophylla, phenology, pollinators, small range, three species in Tabasco. Peer-reviewed article; abstract, full text by subscription.
- PubMed Central, monograph of Ceratozamia (PhytoKeys 208): https://pmc.ncbi.nlm.nih.gov/articles/PMC9849018/ — specimens from Macuspana (Tabasco) listed under Ceratozamia subroseophylla. Peer-reviewed article, open access.
- Species+ (UNEP-WCMC), Ceratozamia: https://speciesplus.net/species#/taxon_concepts/13147/legal — CITES Appendix I for the whole genus since 1 August 1985, Annex A in the European Union. Official CITES and EU database; queried on 30 October 2026.
- BGCI PlantSearch: https://plantsearch.bgci.org/ — no garden declares the species. Global database of garden lists; queried on 30 October 2026.
Bibliography
- Martínez-Domínguez, L., Nicolalde-Morejón, F., González-Aguilar, M.A., Vergara-Silva, F. & Stevenson, D.W. (2024). Ceratozamia gigantea (Zamiaceae), a new species of cycad, endemic to the mountain karst forests of Tabasco, Mexico: what the reproductive structures revealed. Kew Bulletin 79(3): 543–558. https://doi.org/10.1007/s12225-024-10209-0 [Original description; abstract.]
- Martínez-Domínguez, L., Nicolalde-Morejón, F., Vergara-Silva, F. & Stevenson, D.W. (2022). Monograph of Ceratozamia (Zamiaceae, Cycadales): an endangered genus. PhytoKeys 208: 1–102. https://doi.org/10.3897/phytokeys.208.80382 [Treatment of Ceratozamia subroseophylla including the Tabasco specimens; open access.]
- 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.]