Ceratozamia sabatoi

Ceratozamia sabatoi is a small cycad of Mexico, endemic to the Sierra Gorda on the border between the states of Querétaro and Hidalgo, where it grows in the understorey of oak and pine-oak forests between 1,600 and 1,900 m (about 5,250 to 6,230 ft). This species of the genus Ceratozamia was found at the start of the 1990s, during impact studies for a hydroelectric dam, and described in 1993. It has a feature unique in the genus: the outer face of its male cone scales is curved downwards. It is listed as Endangered by the IUCN.

Key facts about Ceratozamia sabatoi

  • Accepted name: Ceratozamia sabatoi Vovides, Vázq.Torres, Schutzman & Iglesias (1993), 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: none recorded, in English or in Mexico (2022 monograph)
  • Natural range: Mexico, Sierra Gorda (Querétaro and Hidalgo), 1,600 to 1,900 m
  • IUCN status: Endangered (EN), assessment published in 2022
  • 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, the low layer of oak and pine-oak forests, on red lateritic clays or on dark humus-rich clay over limestone; no published growing advice
  • Habit and adult size: short trunk, 8 to 30 cm tall and 20 to 35 cm across; 3 to 40 leaves 60 to 129 cm long according to the 2022 monograph (2 to 6 leaves up to 80 cm long in the original description)
  • In the UK, US and Australia: declared by five American gardens; none in the UK or Australia (see In cultivation)
  • Toxicity: no data for the species; treat it as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Ceratozamia sabatoi

It is recognised above all by its male cones: in this species alone, the outer (distal) face of the fertile scales (microsporophylls) is curved downwards (Martínez-Domínguez and colleagues, 2022). Without cones, it is a small plant with a short trunk and arching leaves carrying narrow, flat, flexible leaflets. The 2022 monograph describes it as follows:

  • Trunk: above ground, upright then lying down with age, 8 to 30 cm long and 20 to 35 cm across.
  • Leaves: 3 to 40, 60 to 129 cm long, arching downwards, dark brown with whitish-grey hairs when they emerge, then hairless; petiole 20 to 60 cm long, armed with 5 to 40 very slender prickles up to 2 mm long.
  • Leaflets: 26 to 54 pairs, linear, flat, papery, green on both sides, 13 to 32 cm long and 0.6 to 1.5 cm wide, with a brown point of attachment.
  • Male cones: cylindrical, upright, 11 to 18 cm long and 3.5 to 4.8 cm across, greenish yellow, then covered in blackish hairs.
  • Female cones: cylindrical, upright, 14 to 19.5 cm long and 5.5 to 8.5 cm across, blue-green with blackish hairs when ripe, with a short point.
  • Seeds: oval, 1.2 to 2 cm long, with pinkish-white flesh, then light brown.

The original description of 1993 gives a rather different picture: a globose, partly buried trunk up to 25 cm tall that readily produces offsets; 2 to 6 leaves up to 80 cm long; light green new leaves; leaflets 0.7 to 2.4 cm wide; and female cones 6 to 12 cm long, light blue-green, then green to light blue-brown. These differences, notably in the colour of the new leaves and the size of the female cones, are not discussed by the authors of the monograph; they may reflect different samples and stages, but no source says so.

Hybrids

No natural or garden hybrid has been documented.

Possible confusion

The likeliest confusion is with two other small species of north-eastern Mexico, with which Ceratozamia sabatoi forms a natural group:

  • Ceratozamia kuesteriana, of Tamaulipas: channelled leaflets, upright leaves, a petiole and rachis that turn coppery in adults, and reddish-brown to dark green female cones longer than 13 cm. Ceratozamia sabatoi has flat leaflets, arching leaves, a green petiole and shorter, blue-green female cones (Vovides and colleagues, 1993; Martínez-Domínguez and colleagues, 2022).
  • Ceratozamia zaragozae, of San Luis Potosí: a twisted, unarmed rachis and very narrow leaflets.
  • Ceratozamia latifolia (including the former Ceratozamia microstrobila): much broader leaflets, more than 2.8 cm wide according to the 1993 key.

Without cones, a Ceratozamia is hard to tell from a Zamia: only the two horns on the cone scales settle the matter.

Taxonomy

Ceratozamia sabatoi is accepted by The World List of Cycads, by the 2022 monograph and by the WCVP, the database behind POWO (read via GBIF on 30 October 2026), which records it from north-eastern Mexico; it has no synonym and has never changed name. It was described in 1993 in the journal Novon (3(4): 502–506) by Andrew Vovides and Carlos Iglesias, of the Instituto de Ecología in Xalapa, Mario Vázquez Torres, of the Instituto de Investigaciones Biológicas in Xalapa, and Bart Schutzman, of the University of Florida. The authors already placed it close to Ceratozamia kuesteriana, from which it differs in habit, leaves, female cones, seeds, habitat and the colour of its new leaves.

The 2023 phylogeny by Habib and colleagues, based on 3,954 single-copy nuclear genes, confirmed this relationship: Ceratozamia sabatoi and Ceratozamia zaragozae form a group sister to Ceratozamia kuesteriana, the “kuesteriana subclade”, within the large Mexicana clade. These three species of north-eastern Mexico share narrow, lance-shaped to linear leaflets. The original description also reports 2n = 16 chromosomes, with a karyotype similar to that of the other species of the genus and up to five satellites, against two reported for Ceratozamia kuesteriana.

Etymology and history

The epithet honours Sergio Sabato (1941–1991), a cycad specialist at the botanic garden of the University of Naples, Italy, for his outstanding fieldwork and experimental biology on the neotropical Zamiaceae (Vovides and colleagues, 1993; Haynes, 2022, cited by The World List of Cycads).

The history of the species begins with the Zimapán hydroelectric dam project: during the botanical surveys and impact studies carried out beforehand, the biologist Ricardo Zirahuén found an unknown small-trunked Ceratozamia in a pine-oak forest in Querétaro, and a second population was then located in mixed oak forest on the Hidalgo side, at a similar elevation. Live plants were established at the Francisco Javier Clavijero Botanic Garden in Xalapa for observation, and the karyotype was determined on three of them. The type is a female plant collected in Querétaro on 15 April 1991 by Andrew Vovides (no. 1205, holotype at the XAL herbarium); the 2022 monograph places the type locality in the municipality of San Joaquín, but lists the same collection number under Cadereyta de Montes among the specimens examined. The article appeared in the issue of Novon published on 29 December 1993. Notably, the authors deliberately left out precise localities to discourage indiscriminate commercial collecting.

Common names

No common name is recorded in English, and the 2022 monograph records no vernacular name in Mexico.

In the wild

Ceratozamia sabatoi is endemic to the Sierra Gorda of Querétaro and the neighbouring mountains of north-western Hidalgo. The 2022 monograph places it in the herbaceous understorey of the transition between oak forest and cloud forest, between 1,600 and 1,900 m. Herbarium specimens come from the municipalities of Cadereyta de Montes, Pinal de Amoles, Landa de Matamoros and San Joaquín (Querétaro), and Zimapán and Jacala de Ledezma (Hidalgo); a few labels give elevations outside that range, from 1,235 to 2,000 m.

The original description details the two original sites. In Querétaro, the pine-oak forest is dominated by Pinus teocote and several oaks (Quercus crassifolia, Quercus macrophylla, Quercus germana, Quercus xalapensis), on red lateritic clays. In Hidalgo, a mixed oak forest, richer because of higher rainfall, grows on a dark, humus-rich clay over limestone, with Arbutus xalapensis, Carya ovata, Litsea glaucescens and Prunus serotina, among others. The authors contrast these relatively dry habitats with those of Ceratozamia kuesteriana, which lives in much wetter cloud forests on karst. No study of the pollination or demography of the species has been published.

Conservation status and regulation

Ceratozamia sabatoi is listed as Endangered (EN) on the IUCN Red List, in an assessment by J.D. Bösenberg published in 2022 (category confirmed by the Red List data distributed through GBIF, 30 October 2026). The criteria are given differently by The World List of Cycads (A2acd; B1ab(i,ii,iii,v)) and by the 2022 monograph (A2c; B1ab(i,ii,iv)+2ab(i,ii,iv); C1); both describe a declining population in a small, fragmented range with continuing habitat degradation. As early as 1993, its authors considered it endangered and feared commercial collecting. The Zimapán dam project, which led to its discovery, also shows the pressure that development puts on its small territory.

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+, checked on 30 October 2026). International trade in wild-collected plants for commercial purposes is banned; only artificially propagated plants with the required permits can be traded.

This general information does not replace the official texts: check the regulations in force before buying, importing or exchanging plants, and ask for proof of origin.

Growing Ceratozamia sabatoi

No source describes the cultivation of this species in detail. It is known to be kept in collections: at the Francisco Javier Clavijero Botanic Garden in Xalapa since its description, at Nong Nooch Tropical Botanical Garden in Thailand, which supplied the material for the 2023 phylogenetic study, and in several American gardens. The pointers below are drawn from its habitat and the general rules for the genus; they have not been confirmed by published trials.

  • Light: partial or light shade, like the oak understorey where it lives; protection from strong afternoon sun in hot, dry climates.
  • Soil: free-draining but rich in organic matter; its habitat combines clays and a layer of humus, sometimes over limestone.
  • Watering: regular during growth, letting the surface dry between waterings; much reduced in winter, never leaving the soil sodden.
  • Growth: slow, as in all cycads; no figures are available for the species.

Outdoor and in-ground cultivation

No outdoor planting with a documented result has been published. The American gardens that hold it (Fairchild and Montgomery in southern Florida, the Huntington, Lotusland and San Diego Botanic Garden in California) do not say whether their plants grow outdoors or under glass.

Container cultivation

Its short trunk and modest size make it well suited to a pot, in a free-draining mix rich in organic matter, with protection from frost until hardiness data exist.

In cultivation in the UK, US and Australia

In the United States, BGCI PlantSearch (queried on 30 October 2026) lists five gardens: Fairchild Tropical Botanic Garden and Montgomery Botanical Center (Coral Gables, Florida), the Huntington (San Marino), Lotusland (Santa Barbara) and San Diego Botanic Garden (Encinitas), California. The online catalogue of Montgomery Botanical Center lists 3 accessions, and Fairchild lists the species in its online catalogue. No garden in the United Kingdom or Australia declares it. Outside these countries, BGCI lists the Francisco Javier Clavijero Botanic Garden in Xalapa.

Propagation

Propagation is mainly from seed. The plants are male or female: both sexes and, in cultivation, hand pollination are needed to obtain fertile seed. The original description reports a trunk that readily produces offsets; removing them, possible in principle in clumping Ceratozamia, is not described for this species by any source. No germination data specific to the species have been published. Handle seeds wearing gloves.

Pests and diseases

No pest or disease specific to Ceratozamia sabatoi 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 sabatoi: no dated cultivation report has been published, and no source gives temperature records for its sites. Its altitude (1,600 to 1,900 m) and its oak and pine-oak forests are not enough to infer a hardiness figure.

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, it is best treated as a plant to overwinter frost-free, in a pot, until documented trials exist.

Toxicity and precautions

No toxicity study specific to Ceratozamia sabatoi 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. Dogs, livestock and people can be seriously poisoned. 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 use is known: the 2022 monograph records none for this species.

Frequently asked questions

Where does the name Ceratozamia sabatoi come from?

It honours Sergio Sabato. This professor at the University of Naples, who died in 1991, studied the cycads of tropical America extensively, including in the field.

Where does Ceratozamia sabatoi grow?

In the Sierra Gorda, Mexico. It is found in Querétaro and neighbouring Hidalgo, between 1,600 and 1,900 m, in the understorey of oak or pine-oak forests.

How can I tell it from Ceratozamia kuesteriana?

By the leaves and cones. Ceratozamia sabatoi has flat leaflets, arching leaves and shorter, blue-green female cones; Ceratozamia kuesteriana has channelled leaflets, upright leaves and a coppery petiole. Male cone scales curved downwards occur only in Ceratozamia sabatoi.

Is it endangered?

Yes. The IUCN has listed it as Endangered since the assessment published in 2022. Its range is small and fragmented, and as early as 1993 its authors feared commercial collecting, to the point of withholding precise localities.

Can it take frost?

Nobody knows. No dated cultivation trial and no temperature record from its habitat have been published; overwinter it frost-free until data exist.

Can it be propagated from offsets?

Perhaps, but it is not documented. The original description says the trunk readily produces offsets, but no source describes removing them; seed remains the standard method.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Vovides, A.P., Vázquez Torres, M., Schutzman, B. & Iglesias, C.G. (1993). A new species of Ceratozamia (Zamiaceae) from Querétaro and Hidalgo, Mexico. Novon 3(4): 502–506. [Original description, type, karyotype, habitat.]
  • 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 [Monograph of the genus; 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 [Phylogeny of the genus; open access.]
  • Bösenberg, J.D. (2022). Ceratozamia sabatoi. The IUCN Red List of Threatened Species 2022: e.T42127A69865314. [Red List assessment; category confirmed by GBIF.]
  • 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 etymologies 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.]