Ceratozamia schiblii is a large cycad of Mexico, endemic to the mountains of the eastern part of the state of Oaxaca, where it grows on limestone rocks in cloud forest and oak forest between 1,100 and 1,300 m (about 3,610 to 4,270 ft). This species of the genus Ceratozamia, described in 2022, had until then been confused with Ceratozamia robusta. It is recognised by its brown new leaves, its olive-green male cones and above all its female cones carried on a very long stalk, which hang down when ripe. The IUCN has not yet assessed it.
Key facts about Ceratozamia schiblii
- Accepted name: Ceratozamia schiblii Pérez-Farr. & Gut.Ortega (2022), 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; populations formerly identified as Ceratozamia robusta
- Family: Zamiaceae, order Cycadales
- Common names: none recorded
- Natural range: Mexico, eastern Oaxaca (southern foothills of the Sierra Norte: municipalities of Santiago Lachiguiri, Santa María Guienagati and Guevea de Humboldt), 1,100 to 1,300 m
- IUCN status: Not Evaluated (NE)
- CITES and other protection: CITES Appendix I (whole genus, since 1985); Annex A in the European Union, seeds included
- Documented hardiness: no data, neither from cultivation nor as temperature records from its habitat (see Cold hardiness)
- Light and soil: in the wild, a rock-dwelling plant of karst, in cloud forest and oak forest; no published growing advice
- Habit and adult size: unbranched trunk 0.2 to 2.2 m tall and 20 to 24 cm across; 15 to 24 leaves 1.6 to 2.6 m long
- In the UK, US and Australia: no garden declares it (see In cultivation)
- Toxicity: no data for the species; treat it as poisonous, like all cycads (see Toxicity and precautions)
How to recognise Ceratozamia schiblii
Its authors single out three characters: brown new leaves, a female cone that hangs at the end of a stalk more than 20 cm long, and a male cone that is green when mature. It also has the largest number of leaflet pairs and one of the longest rachises in its group of species. The original description (Pérez-Farrera and colleagues, 2022) gives the following details:
- Trunk: cylindrical, upright, leaning in old plants, never branched, 20 to 220 cm tall and 20 to 24 cm across, covered with old leaf bases.
- Leaves: 15 to 24, in an open crown, upright, 161 to 262 cm long; brown when they emerge, then olive green. Petiole 44 to 84 cm long, densely armed with thick prickles; rachis 112 to 178 cm long, with spaced prickles.
- Leaflets: 34 to 45 pairs, leathery, linear, slightly to clearly sickle-shaped, with faint veins and a green point of attachment; the middle ones measure 30 to 40 cm by 3 to 4.5 cm.
- Male cones: solitary, conical, upright, olive green when mature, 22 to 33 cm long and 6 to 7 cm across.
- Female cones: solitary, cylindrical, upright when they emerge, then hanging, 25 to 28 cm long and 10.7 to 12 cm across, brown when ripe; peduncle 20 to 21.5 cm long.
- Seeds: ovoid, 2.6 to 3.1 cm long, with cream flesh turning orange-brown.
The female cones appear around May; they first stand upright, then lean over as they ripen and become heavier.
Hybrids
No natural or garden hybrid has been documented.
Possible confusion
Ceratozamia schiblii belongs to the Ceratozamia robusta complex, a group of large species with thick trunks, long leaves and big cones that look much alike. It is the only member of this group whose female cone hangs down when ripe (Pérez-Farrera and colleagues, 2022).
- Ceratozamia robusta: reddish-brown new leaves, papery leaflets, an upright female cone on a short stalk. The plants of eastern Oaxaca long carried this name.
- Ceratozamia aurantiaca, of northern Oaxaca: the only other species of the complex with leathery leaflets, but its new leaves are orange.
- Ceratozamia mixeorum, of the neighbouring Sierra Mixe: the likeliest confusion, because its female cone also has a very long stalk. It differs in its bright pea-green new leaves, its narrower (2.1 to 2.9 cm) and more numerous leaflets (50 to 77 pairs), its shorter leaves (1.5 to 2 m), its sometimes branched trunk and its higher elevation, 1,440 to 1,900 m. It belongs to another lineage of the genus, close to Ceratozamia matudae.
The other species of the complex, Ceratozamia subroseophylla, Ceratozamia dominguezii, Ceratozamia oliversacksii and Ceratozamia leptoceras, all have upright female cones and papery or membranous leaflets. Without cones, a young Ceratozamia can also be mistaken for a Zamia.
Taxonomy
Ceratozamia schiblii is accepted by The World List of Cycads and by the WCVP, the database behind POWO (read via GBIF on 30 October 2026), which records it from south-western Mexico; it has no synonym. The monograph of the genus published the same year does not treat it.
The species was described in July 2022 in the journal Taxonomy by Miguel Ángel Pérez-Farrera, José Said Gutiérrez-Ortega and five co-authors, including Timothy Gregory (University of California Botanical Garden at Berkeley), Jeffrey Chemnick (Ganna Walska Lotusland, California) and Michael Calonje (Montgomery Botanical Center, Florida). The authors had examined all the Ceratozamia specimens in the MEXU, HEM and XAL herbaria: only those from the municipality of Santiago Lachiguiri, in the eastern highlands of Oaxaca, matched no known species. These plants had been filed under Ceratozamia robusta because of their large trunks, long leaves and big cones.
To check that they formed a distinct species, the authors compared 87 adult plants of six species of the Ceratozamia robusta complex on seven leaf measurements. A discriminant analysis assigned the 16 plants from eastern Oaxaca to their own group, without error, and all the morphological distances between species were significant. According to the authors, this description brings the complex to seven species: Ceratozamia robusta, Ceratozamia subroseophylla, Ceratozamia aurantiaca, Ceratozamia dominguezii, Ceratozamia oliversacksii, Ceratozamia leptoceras and Ceratozamia schiblii. Their analyses also clearly separate Ceratozamia dominguezii from Ceratozamia subroseophylla, two species that the 2022 monograph merged under the second name; The World List of Cycads keeps them apart, whereas the WCVP follows the monograph.
The authors also note that the species of the Gulf of Mexico slope are more robust than those of the Pacific slope, and that eastern Oaxaca corresponds to a former refuge of tropical flora during the climatic fluctuations of the Neogene.
Etymology and history
The epithet honours Leo Schibli (1958–2004), a founding member of the Sociedad para el Estudio de los Recursos Bióticos de Oaxaca (SERBO), an association of naturalists in Oaxaca. His field explorations and collections in the state led to the discovery of several new cycads (Pérez-Farrera and colleagues, 2022).
The type is a male plant collected on 30 November 2021 at 1,290 m in the municipality of Santiago Lachiguiri by Miguel Ángel Pérez-Farrera (no. 4074) and his team; the holotype is kept at the HEM herbarium in Tuxtla Gutiérrez, with isotypes at XAL and MEXU. Older collections had been made in the region in 1984, 1991 (Guevea de Humboldt) and 1996. No source documents its introduction into cultivation.
Common names
No common name is recorded, in English or in any other language.
In the wild
Ceratozamia schiblii is endemic to the highlands of eastern Oaxaca, on the last southern foothills of the Sierra Norte, close to the Sierra Mixe. It is known from the municipalities of Santiago Lachiguiri and Santa María Guienagati, and from older collections in Guevea de Humboldt. It is a rock-dwelling plant, growing between 1,100 and 1,300 m in cloud forests and oak forests on karst (Pérez-Farrera and colleagues, 2022).
The accompanying flora mixes conifers, oaks and tropical plants: Pinus chiapensis, Pinus oocarpa, Cupressus lusitanica, Quercus laeta, Podocarpus matudae, Oreomunnea mexicana, Chamaedorea palms, the tree fern Cyathea divergens and many aroids. No study of pollination, germination or population dynamics has been published.
Conservation status and regulation
Ceratozamia schiblii has not yet been assessed by the IUCN (Not Evaluated, according to The World List of Cycads, confirmed by GBIF on 30 October 2026), and its description proposes no preliminary assessment. Its range appears small, but no data on numbers or threats have been published.
Like the whole genus, it has been covered by CITES Appendix I since 1 August 1985 (the genus had been in Appendix II since 1977), 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 list the species under its own name (checked on 30 October 2026), but the listing covers the entire genus. International trade in wild-collected plants for commercial purposes is banned; only artificially propagated plants with the required permits can be traded.
In practice, plants from this region may have circulated under the name Ceratozamia robusta. Buy only seed-grown plants with documents of origin. This general information does not replace the official texts: check the regulations in force before buying, importing or exchanging plants.
Growing Ceratozamia schiblii
No source describes the cultivation of this species, and no cultivation report has been documented. The pointers below are drawn only from its habitat and from the general rules for the genus; they have not been confirmed by published trials.
- Light: partial shade or filtered light, as in cloud forest; avoid harsh sun.
- Soil: very free-draining, with a mineral component to recall the limestone rocks where it grows.
- Watering: regular during growth, never leaving water standing, reduced in winter.
- Space: it is a large species, with leaves more than 2 m long armed with thick prickles; allow room and wear gloves.
Outdoor and in-ground cultivation
No outdoor planting of this species has been documented anywhere.
Container cultivation
Young plants can be grown in a large pot in a free-draining mix; adults, with their long leaves, soon outgrow most containers. Keep them frost-free until hardiness data exist.
In cultivation in the UK, US and Australia
No botanic garden in the United Kingdom, the United States or Australia declares this species: BGCI PlantSearch lists only the Francisco Javier Clavijero Botanic Garden in Xalapa, Mexico, and the online catalogue of Montgomery Botanical Center lists no accession (both queried on 30 October 2026). Plants from eastern Oaxaca grown before 2022 may carry the name Ceratozamia robusta.
Propagation
Propagation is from seed. The plants are male or female, and hand pollination is needed to obtain fertile seed in cultivation. No germination data specific to the species have been published; the original description shows seedlings in the wild without further detail. Handle seeds wearing gloves.
Pests and diseases
No pest or disease specific to Ceratozamia schiblii has been documented. In cultivated Ceratozamia, growers mainly report rot in cold, sodden soil and leaf scorch after sudden exposure to full sun.
Cold hardiness
No data exist for Ceratozamia schiblii: no cultivation report, and no published temperature record from its sites. The presence of pines and oaks in its habitat is not enough to infer frost tolerance.
Mediterranean and European experience
No cultivation of this species has been reported in Europe, and the Jardin zoologique tropical in La Londe-les-Maures (Var, on the French Riviera) has published no observation of it. European results for the genus concern other species and cannot be transferred to it.
United Kingdom, United States and Australia
No dated cold record and no commercial hardiness rating have been published. For lack of data, keep it frost-free until documented trials exist.
Toxicity and precautions
No toxicity study specific to Ceratozamia schiblii has been published. The risk is well documented in other cycads: their tissues, and above all their seeds, contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, a compound harmful to the liver and nervous system. In the absence of evidence to the contrary, treat the plant as poisonous: keep seeds and leaves out of reach of children and animals, wear gloves to clean seeds, and if any part is swallowed, call a poison centre, a doctor or a vet straight away.
Traditional uses
No traditional use has been reported.
Frequently asked questions
Where does Ceratozamia schiblii grow?
In eastern Oaxaca, Mexico. It lives on limestone rocks in cloud forest and oak forest, between 1,100 and 1,300 m, near the Sierra Mixe.
How can I recognise it?
By its hanging female cone. The cone is carried on a stalk more than 20 cm long, a feature unique in the Ceratozamia robusta complex. Brown new leaves and an olive-green male cone complete the identification.
How does it differ from Ceratozamia mixeorum?
Mainly in the colour of the new leaves and the width of the leaflets. Ceratozamia mixeorum, a neighbour, also has a long-stalked cone, but its new leaves are bright pea green and its leaflets narrower and more numerous. It also grows higher, above 1,400 m.
Is it a former Ceratozamia robusta?
Yes. The plants of eastern Oaxaca were filed under Ceratozamia robusta until 2022 because of their large size. A study of their measurements showed that they form a separate species.
Is it endangered?
Nobody knows yet. The IUCN has not assessed it, and no data on its populations have been published. Like the whole genus, it is listed in CITES Appendix I.
Can it take frost?
Nobody knows. No documented trial exists: overwinter it frost-free.
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 schiblii: https://cycadlist.org/scientific_name/1017 — authors, place of publication, type, range (Oaxaca), 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 schiblii: https://api.gbif.org/v1/species/213762089 — accepted name, place of publication (Taxonomy 2: 330, 2022), south-western Mexico. Kew data, the basis of POWO, distributed by GBIF; consulted on 30 October 2026.
- Taxonomy (MDPI), description of Ceratozamia schiblii (Pérez-Farrera and colleagues, 2022): https://doi.org/10.3390/taxonomy2030025 — description, type, habitat, associated flora, morphometrics of the Ceratozamia robusta complex, key, comparison with Ceratozamia mixeorum, etymology. Peer-reviewed article, open access (PDF also distributed by The World List of Cycads); primary source.
- Species+ (UNEP-WCMC), Ceratozamia: https://speciesplus.net/species#/taxon_concepts/13147/legal — whole genus in CITES Appendix I since 1 August 1985 and in Annex A in the European Union; the species is not listed under its own name. Official CITES and EU database; checked on 30 October 2026.
- Commission Regulation (EU) 2026/1383: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=OJ:L_202601383 — annexes to Regulation (EC) No 338/97 in force since 29 June 2026. Official text.
- BGCI PlantSearch: https://plantsearch.bgci.org/ — one garden declaring the species (Mexico). Global database of garden lists; queried on 30 October 2026.
Bibliography
- Pérez-Farrera, M.A., Gutiérrez-Ortega, J.S., Gregory, T.J., Chemnick, J., Salas-Morales, S., Calonje, M. & Díaz-Jiménez, P. (2022). Ceratozamia schiblii (Zamiaceae): a new cycad species from the eastern mountains of Oaxaca, Mexico. Taxonomy 2(3): 324–338. https://doi.org/10.3390/taxonomy2030025 [Original description; open access. Primary source.]
- 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.]