Ceratozamia chimalapensis

Ceratozamia chimalapensis is a cycad of eastern Oaxaca, in southern Mexico, endemic to the Chimalapas region and the Sierra Atravesada, where it grows between 290 and 1,000 m (about 950 to 3,300 ft). Described in 2008, this species of the genus Ceratozamia has long leaves with many narrow leaflets and particularly long female cones. Known locally as “mazacopa”, it has documented traditional uses, and the IUCN Red List assesses it as Endangered.

Key facts about Ceratozamia chimalapensis

• Accepted name: Ceratozamia chimalapensis Pérez-Farr. & Vovides (2008), accepted by The World List of Cycads (version 2026.08.15), by the 2022 monograph of the genus and by the World Checklist of Vascular Plants (WCVP, the database behind POWO, read via GBIF)
• Former names and synonyms: none
• Family: Zamiaceae, order Cycadales
• Common names: no English name; “mazacopa” in Oaxaca
• Natural range: Mexico, eastern Oaxaca (Chimalapas, Sierra Atravesada), 290 to 1,000 m
• IUCN status: Endangered (EN, criteria A3cd+4cd; B2ab(ii,iii,v)), assessment published in 2022
• CITES and other protection: CITES Appendix I (whole genus, since 1985); Annex A in the European Union
• Documented hardiness: no data (see Cold hardiness)
• Light and soil: in the wild, oak forest on clay soils according to the 2022 monograph; evergreen tropical forest according to Habib and colleagues (2023)
• Habit and adult size: trunk 20 to 60 cm; 7 to 24 leaves, 0.66 to 2.5 m long
• In the UK, US and Australia: Montgomery Botanical Center (Florida) and Atlanta Botanical Garden (Georgia); none in the UK or Australia
• Toxicity: no toxicity data specific to the species, but the ground seed is used locally as a rat poison; treat it as poisonous (see Toxicity and precautions)

How to recognise Ceratozamia chimalapensis

Its foliage recalls that of the narrow-leafleted species of Chiapas, but its female cones are clearly longer, with 11 to 12 vertical rows of scales and more than 90 seeds per cone. The 2022 monograph by Martínez-Domínguez and colleagues describes it as follows:

• Trunk: above ground, upright or decumbent, 20 to 60 cm long and 15 to 30 cm across.
• Leaves: 7 to 24, ascending, 66 to 250 cm long, brown when they emerge; petiole 40 to 70 cm, with 20 to 30 thin prickles; rachis prickly.
• Leaflets: 36 to 70 pairs, lanceolate, papery, light green; median leaflets 27 to 46 cm by 1.2 to 1.8 cm, 0.8 to 1.3 cm apart; articulation brown to yellowish brown.
• Male cones: cylindrical, upright, 25 to 40 cm by 3 to 5 cm, greenish yellow turning cream; male scales elliptic, with curved horns.
• Female cones: cylindrical, upright, 35 to 40 cm by 7.3 to 10.6 cm, green with blackish hairs and an acuminate tip; 99 to 192 scales with straight, slender horns.
• Seeds: oval, 2 to 3 cm, with yellow flesh turning light brown.

Hybrids

No natural or garden hybrid has been documented.

Possible confusion

In its leaves, Ceratozamia chimalapensis resembles two species from Chiapas:

• Ceratozamia mirandae and Ceratozamia alvarezii have comparable foliage, but shorter female cones and spherical rather than oval seeds;
• Ceratozamia alvarezii is also a smaller plant, with an often branched trunk and leaflets less than 1 cm wide.

In the identification key of the monograph, its elliptic male scales with curved horns separate it from Ceratozamia vovidesii, whose male scales are obconical with straight horns. Away from its place of origin, a plant without cones is very hard to identify with certainty.

Taxonomy

Ceratozamia chimalapensis has never changed name. It is accepted by The World List of Cycads and by the WCVP, which records its publication in the Botanical Journal of the Linnean Society 157, page 169.

It was described in 2008 in an article by Andrew Vovides, Miguel Angel Pérez-Farrera, Jorge González-Astorga and Carlos Iglesias, which included comments on its habitat and relationships; The World List of Cycads and the WCVP attribute the name to Pérez-Farrera and Vovides.

The phylogenomic study by Habib and colleagues (2023) places it in the norstogii subclade of the Miqueliana clade, with Ceratozamia norstogii, Ceratozamia alvarezii, Ceratozamia mirandae and Ceratozamia vovidesii; the authors suggest including it in the Ceratozamia norstogii complex, with which it shares characters of the leaves and cones. One of their datasets makes it the closest relative of Ceratozamia alvarezii. A 2024 study of cone morphology notes that the elliptic shape of its male scales is a novelty specific to this clade.

Etymology and history

The epithet refers to the Chimalapas, a vast forested region of eastern Oaxaca, in recognition of its biological richness and of the floristic diversity of the state (Haynes, 2022, as quoted by The World List of Cycads; the 2022 monograph gives the same explanation).

The type specimen, a female plant, was collected on 21 January 2002 by Miguel Angel Pérez-Farrera (number 2622) at Chimalapa; the holotype is kept in the HEM herbarium, with isotypes at MEXU, MO and XAL. Older collections exist: the monograph cites a specimen from 1946 (Santiago Niltepec, 1,000 m) and another from 1995 (Santa María Chimalapa, 290 m).

Common names

There is no English name. The 2008 description, cited by the 2022 monograph, gives the local name “mazacopa” in Oaxaca; its origin is not explained.

In the wild

Ceratozamia chimalapensis is endemic to Oaxaca, in the Sierra Atravesada and the Chimalapas region, between 290 and 1,000 m. The WCVP gives its range as south-western Mexico.

The sources describe its habitat differently: the 2022 monograph places it in oak forest on clay soils, whereas the study by Habib and colleagues (2023) groups it with the species of evergreen tropical forest. Besides the type, only two herbarium specimens are cited, and the monograph states that the species is known only from a narrow area, where several individuals have been recorded.

Conservation status and regulation

Ceratozamia chimalapensis is assessed as Endangered (EN, criteria A3cd+4cd; B2ab(ii,iii,v)) on the IUCN Red List, in the assessment by A.P. Vovides published in 2022. The category is given by The World List of Cycads and confirmed by the Red List data relayed by GBIF (checked on 30 October 2026). The 2022 monograph, written before this assessment was published, judged the data insufficient to propose a category.

Like the whole genus, it has been listed in CITES Appendix I since 1 August 1985, and in 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). Species+ lists it by name; seeds are covered as well as plants (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 chimalapensis

No growing guide and no grower’s report have been published. Its low to middle altitude habitat in eastern Oaxaca points to a plant for a warm climate, to be kept frost-free; the general conditions of the genus (partial shade, free-draining soil, regular but not excessive watering) apply, with that reservation.

Outdoor and in-ground cultivation

No outdoor planting has been documented. Only frost-free tropical or subtropical gardens could be considered, in light shade and well-drained soil; this is inferred from its habitat, not tested.

Container cultivation

No container-growing report has been published. With leaves up to 2.5 m long, the plant needs space; a large pot of free-draining compost, bright shade and a heated glasshouse or conservatory in winter would follow its habitat.

In cultivation in the UK, US and Australia

In the United States, Montgomery Botanical Center (Coral Gables, Florida) lists three accessions in its online catalogue and declares the species to BGCI PlantSearch, as does Atlanta Botanical Garden (Georgia). The other holders declared to BGCI are in Mexico: the Clavijero botanic garden in Xalapa and the Jardín Etnobotánico de Oaxaca. No garden in the UK or Australia declares it (BGCI and Montgomery checked on 30 October 2026). A BGCI listing shows that a garden has declared the species at some point, not that a living plant is there today.

Propagation

No data specific to the species. The plant has separate male and female individuals and is propagated from seed. According to the monograph, a female cone carries more than 90 seeds.

Pests and diseases

No pest or disease has been documented for this species.

Cold hardiness

There are no data on the cold tolerance of Ceratozamia chimalapensis. No climate data have been published for its sites, and its altitude of 290 to 1,000 m in southern Mexico gives no reason to expect any frost tolerance.

Mediterranean and European experience

No cultivation has been reported in France or Italy, in the ground or in a pot. At the Jardin zoologique tropical in La Londe-les-Maures (Var, on the French Riviera), no observation of it has been published. 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. The gardens that hold it in Florida and Georgia do not state its growing conditions; in the UK it would need a heated glasshouse.

Toxicity and precautions

No analysis concerns this species, but a local use indirectly confirms that the seeds are toxic: according to the 2008 description, the ground seed is used as a rat poison. As in other cycads, its seeds and leaves should be assumed to contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, a compound harmful to the liver and nervous system. The seed flesh is nevertheless eaten locally, which does not make it safe. Keep seeds and leaves out of reach of children and pets, and call a poison centre, a doctor or a vet straight away if any part is swallowed.

Traditional uses

The 2008 description, cited by the 2022 monograph, records three uses: the seed flesh (sarcotesta) is eaten, the ground seed is used as a rodenticide and, mixed with honey, as an insecticide. No detail is given on quantities or preparation.

Frequently asked questions

Where does Ceratozamia chimalapensis grow?

In eastern Oaxaca, Mexico, in the Sierra Atravesada and the Chimalapas region, between 290 and 1,000 m.

What does “mazacopa” mean?

It is the local name of the plant in Oaxaca, recorded in the 2008 description. Its origin is not explained.

How can it be recognised?

By its many narrow leaflets (36 to 70 pairs) and above all by its female cones, 35 to 40 cm long, with oval seeds, larger than those of Ceratozamia mirandae and Ceratozamia alvarezii.

Is it poisonous?

Yes, it should be treated as such. Its ground seed is used as a rat poison, and all the cycads studied contain serious toxins.

Is it endangered?

Yes. It has been assessed as Endangered by the IUCN since 2022 and is known only from a narrow area of Oaxaca.

Can it be grown outdoors?

Only in frost-free climates, and even there no result has been published. Elsewhere it is a plant for a heated glasshouse or conservatory, to be bought only with CITES documents.

Further reading on Succulentes

• How to Grow Cycads from Seed: Germination, Seedling Care and Propagation Setup
• Is Sago Palm Toxic to Dogs, Cats & Children? What to Know

Sources

Reference sites

• The World List of Cycads (version 2026.08.15), Ceratozamia chimalapensis: https://cycadlist.org/scientific_name/20 — authors, publication, type, range, IUCN status (EN, 2022), 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 chimalapensis: https://api.gbif.org/v1/species/207874529 — accepted name, Bot. J. Linn. Soc. 157: 169 (2008), south-western Mexico. Kew data, the basis of POWO, distributed by GBIF; consulted on 30 October 2026.
• GBIF, IUCN Red List data for Ceratozamia chimalapensis: https://api.gbif.org/v1/species/4000160/iucnRedListCategory — Endangered (EN). IUCN Red List data distributed by GBIF; consulted on 30 October 2026.
• Species+ (UNEP-WCMC), Ceratozamia chimalapensis: https://speciesplus.net/species#/taxon_concepts/65505/legal — CITES Appendix I since 1 August 1985, Annex A in the European Union. Official CITES and EU database; queried on 30 October 2026.
• PubMed Central, monograph of Ceratozamia (PhytoKeys 208): https://pmc.ncbi.nlm.nih.gov/articles/PMC9849018/ — description, type, range, habitat, local name, uses, identification key. Peer-reviewed article, open access; reread on 30 October 2026.
• PubMed Central, Habib et al. (2023), Plants 12(3): 478: https://pmc.ncbi.nlm.nih.gov/articles/PMC9921377/ — phylogenetic position, habitat. Peer-reviewed article, open access.
• BGCI PlantSearch: https://plantsearch.bgci.org/ — four gardens declaring the species (Montgomery Botanical Center, Atlanta Botanical Garden, Jardín Botánico Francisco Javier Clavijero, Jardín Etnobotánico de Oaxaca). Global database of garden lists; queried on 30 October 2026.
• Montgomery Botanical Center, living collection (BG-BASE catalogue): https://www.montgomerybotanical.org/research/living-collection/ — three accessions (20020073, 20030103, 20240112). Botanic garden catalogue; consulted on 30 October 2026.

Bibliography

• Vovides, A.P., Pérez-Farrera, M.A., González-Astorga, J. & Iglesias, C. (2008). A new species of Ceratozamia (Zamiaceae) from Oaxaca, Mexico with comments on habitat and relationships. Botanical Journal of the Linnean Society 157(2): 169–175. https://doi.org/10.1111/j.1095-8339.2008.00793.x [Original description; data as reported by the 2022 monograph and The World List of Cycads.]
• 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 [Description, range, habitat, local name, uses; open access.]
• Habib, S., Gong, Y., Dong, S., Lindstrom, A., Stevenson, D.W., Wu, H. & Zhang, S. (2023). Phylotranscriptomics shed light on intrageneric relationships and historical biogeography of Ceratozamia (Cycadales). Plants 12(3): 478. https://doi.org/10.3390/plants12030478 [Phylogenetic position; open access.]
• Martínez-Domínguez, L., Nicolalde-Morejón, F., Vergara-Silva, F., Gernandt, D.S., Huesca-Domínguez, I. & Stevenson, D.W. (2024). Evolutionary trends of reproductive phenotype in Cycadales: an analysis of morphological evolution in Ceratozamia. Annals of Botany 134(4): 631–650. https://doi.org/10.1093/aob/mcae058 [Shape of the male scales.]
• Vovides, A.P. (2022). Ceratozamia chimalapensis. The IUCN Red List of Threatened Species 2022: e.T187825A1827801. https://doi.org/10.2305/IUCN.UK.2022-1.RLTS.T187825A1827801.en [Current assessment, Endangered; category given by The World List of Cycads and GBIF, reference found on Crossref.]
• Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. https://doi.org/10.11646/phytotaxa.550.1.1 [Source of the etymology given 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. https://doi.org/10.5281/zenodo.21958524 [Reference checklist.]