Ceratozamia zoquorum

Ceratozamia zoquorum is a cycad of south-eastern Mexico, endemic to the northern mountains of Chiapas according to the 2022 monograph of the genus, where it grows on limestone outcrops in evergreen tropical forest and oak forest between about 500 and 1,150 m (about 1,640 to 3,770 ft). This species of the genus Ceratozamia, described in 2001, is named after the Zoque people, who live in that region. It has broad, oblong, leathery leaflets, few in number, and young leaves with a pink petiole. It is listed as Critically Endangered by the IUCN, whose Red List also includes the closely related Ceratozamia becerrae under this name.

Key facts about Ceratozamia zoquorum

  • Accepted name: Ceratozamia zoquorum Pérez-Farr., Vovides & Iglesias (2001), 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: no current synonym for The World List of Cycads and the WCVP; Ceratozamia becerrae was placed under it from 2017 to 2020, and the IUCN Red List still treats it as a synonym (see Taxonomy)
  • Family: Zamiaceae, order Cycadales
  • Common names: none recorded
  • Natural range: Mexico, northern mountains of Chiapas (municipalities of Solosuchiapa and Tila), 500 to 1,150 m; The World List of Cycads also gives Tabasco
  • IUCN status: Critically Endangered (CR), assessment published in 2022; the Red List includes Ceratozamia becerrae in it as a synonym
  • CITES and other protection: CITES Appendix I (whole genus, since 1985); Annex A in the European Union, seeds included; “in danger of extinction” (P) in the Mexican standard NOM-059-SEMARNAT-2010
  • Documented hardiness: no data for the species (see Cold hardiness)
  • Light and soil: in the wild, karst outcrops and cliffs in evergreen tropical forest and oak forest; no published growing advice
  • Habit and adult size: short trunk, 12 to 30 cm, above ground or half buried, with 2 to 17 leaves 0.5 to 2.2 m long (2022 monograph); trunk 10 to 48 cm, branching with age, with 1 to 5 leaves 0.8 to 3.7 m long (original description)
  • In the UK, US and Australia: declared by three 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 zoquorum

Its broad, oblong, leathery leaflets, few in number and widely spaced, with a long-pointed, asymmetrical tip, place it in a small group of very similar species. Its young leaves, with a pink petiole and rachis, and the long stalk of its female cone help to identify it. The 2022 monograph describes it as follows:

  • Trunk: 12 to 30 cm long and 8 to 15 cm across, above ground or half buried, upright; scale leaves (cataphylls) reddish brown with a brown felt.
  • Leaves: 2 to 17, 46 to 216 cm long, drooping; light green or brown and glaucous at emergence, with whitish-grey hairs. Petiole 23 to 111 cm and rachis 18 to 114 cm long, pink at emergence, then yellowish green; petiole unarmed or with 3 to 27 slender prickles 1 to 1.5 mm long.
  • Leaflets: 6 to 17 pairs, oblong to oblanceolate, leathery, often curved at the base, glaucous on one or both faces; middle leaflets 22 to 37 cm long and 3.9 to 5.6 cm wide (up to 7 cm), 4.6 to 11 cm apart.
  • Male cones: solitary or in pairs, cylindrical, upright, 11 to 25 cm long and 2.8 to 4.3 cm across, green with blackish hairs, then yellowish cream; stalk 5 to 13 cm long.
  • Female cones: solitary, cylindrical, upright, 15 to 26 cm long and 7.5 to 9.5 cm across, green with reddish-brown hairs, then with brown to blackish hairs; stalk 5 to 18.5 cm long, upright or hanging; scales with straight or curved horns 7 to 9 mm long.
  • Seeds: oval, 2 to 2.8 cm long, with pinkish-white flesh turning light brown.

The original description (Pérez-Farrera, Vovides and Iglesias, 2001) gives: a plant sometimes growing on rock; a subglobose to cylindrical trunk, partly underground, branching with age, 10 to 48 cm long and 13 to 48 cm across; 1 to 5 ascending to lying leaves, 81 to 374 cm long and 42 to 75 cm wide, coiled when young (circinate vernation) and covered at emergence with a waxy bluish-grey bloom; petiole 20 to 124 cm and rachis 40 to 156 cm long, bloomy, unarmed or with a few short, widely spaced prickles that disappear in old plants; 5 to 16 pairs of leathery, flat, bloomy, oblong to oblanceolate leaflets, 23 to 38.5 cm long and 3.2 to 6.5 cm wide, with 27 to 42 veins clearly visible beneath; an upright male cone, olive green to light green, then yellow to cream, 11.2 to 29 cm long, on a stalk 4 to 10.5 cm long; a cylindrical to barrel-shaped female cone, hanging, dark green then olive green, 22 to 26 cm long and 9.5 to 9.8 cm across, on a stalk 6 to 7 cm long; oval seeds 2.1 to 2.2 cm long; and a chromosome number of 2n = 16. The position of the female cone is the main disagreement with the monograph, which describes it as upright: the original description and the description of Ceratozamia santillanii (2009) both make the female cone hanging at maturity the character that separates Ceratozamia zoquorum from its neighbours.

Hybrids

No natural or garden hybrid has been documented.

Possible confusion

Ceratozamia zoquorum forms with Ceratozamia becerrae and Ceratozamia santillanii a group of “cryptic” species, close in geography and almost identical to the eye: all have oblong, leathery leaflets with an asymmetrical tip (Martínez-Domínguez and colleagues, 2022).

  • Ceratozamia santillanii, known from a single locality in Chiapas: a smaller plant; its female cone has a stalk 3 cm long at most, against more than 3 cm in Ceratozamia zoquorum (key of the 2022 monograph). The original description of Ceratozamia santillanii (2009) separated them differently: upright female cone, veins invisible beneath and leaflets 3.4 to 7.5 cm apart in Ceratozamia santillanii, against a hanging female cone, visible veins and leaflets 1.7 to 2.4 cm apart in Ceratozamia zoquorum.
  • Ceratozamia becerrae, of the Sierra Madrigal on the borders of Chiapas and Tabasco: very close; in the key of the monograph the two are separated only by geography, while anatomists separate them by the absence of certain supporting tissues in the leaflets of Ceratozamia becerrae (see Taxonomy).
  • Ceratozamia sancheziae, of the highlands of Chiapas: its linear, papery and numerous leaflets (20 to 35 pairs), 3 cm wide at most, make it easy to tell apart.

The three cryptic species are reliably separated by a region of nuclear ribosomal DNA, the ITS. A plant without cones and without a known origin therefore cannot be identified with certainty. Without cones, a young Ceratozamia can also be mistaken for a Zamia.

Taxonomy

Ceratozamia zoquorum 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 south-eastern Mexico. Its limits, however, have changed considerably with the studies of its neighbours.

A species described in 2001

Miguel Ángel Pérez-Farrera, Andrew Vovides and Carlos Iglesias described it in 2001 in the Botanical Journal of the Linnean Society (137(1): 77–80), in a paper entitled “A new species of Ceratozamia (Zamiaceae) from Chiapas, Mexico”. They compared it with Ceratozamia miqueliana, from which it differs in the coiled vernation of its leaves, its hanging female cone with reddish down and its shorter, thicker stalks; a hanging cone is also found in Ceratozamia matudae, Ceratozamia zaragozae and Ceratozamia mixeorum, which differ in their leaves, leaflets and trunk. They had grown it for at least three years, next to Ceratozamia miqueliana, under two climates: at the University of Sciences and Arts of Chiapas (UNICACH) in Tuxtla Gutiérrez, at 560 m, and at the Francisco Javier Clavijero Botanic Garden in Xalapa, at 1,250 m. A curiosity of the paper: after the heading, the species is often called “Ceratozamia zoquensis” in the text (habitat, discussion, key), but the name published in the description is zoquorum.

The Ceratozamia becerrae episode

Ceratozamia becerrae, described in 2004 from Tabasco and Chiapas, was placed in synonymy with Ceratozamia zoquorum in 2017 by Lilí Martínez-Domínguez and colleagues, in a study of cryptic diversity in the Ceratozamia miqueliana complex. In 2020, Andrew Vovides and colleagues reinstated it as a distinct species on the basis of leaflet anatomy: according to the 2022 monograph, Ceratozamia zoquorum has bundles of supporting fibres linking the veins to the faces of the leaflet and a lignified layer under the upper epidermis, which are absent or almost absent in Ceratozamia becerrae. The World List of Cycads, the WCVP and the 2022 monograph accept both species, but the monograph considers that the anatomical key is not enough to identify them and relies mainly on DNA to separate them.

The IUCN Red List has not followed this reinstatement. The Red List data distributed through GBIF (30 October 2026) treat Ceratozamia becerrae as a synonym of Ceratozamia zoquorum, and the 2022 assessment of Ceratozamia zoquorum as Critically Endangered therefore covers both names. This explains why Ceratozamia becerrae has no current assessment of its own.

The boundary with Ceratozamia sancheziae

In 2022, the monograph revised the Ceratozamia of the municipalities of Yajalón, Tila, Altamirano and Tenejapa, and divided them between Ceratozamia zoquorum and Ceratozamia sancheziae. It assigns the populations of Tila to Ceratozamia zoquorum, stresses the strong variation of the species and leaves open the identity of some plants collected in the municipality of Yajalón.

Type and place in the genus

The type is a male plant collected on 18 November 1998 by Pérez-Farrera (no. 1732) in the northern mountains of Chiapas; the holotype is stated to be in the CHIP herbarium, but the authors of the 2022 monograph did not see it. The original description also calls “isotype” a female plant with a different number and date (Pérez-Farrera 905, 17 April 1996, at XAL, MEXU and MO), and deliberately omits the locality, to avoid the decimation of the population. Its position in the phylogeny remains unstable: in the 2024 study of the evolution of the cones of the genus, it changes place and clade depending on the analysis, and it is among the species whose female cone has become smaller during evolution (Martínez-Domínguez and colleagues, 2024).

Etymology and history

The epithet zoquorum, a Latin genitive plural, means “of the Zoques”: it honours the Zoque culture, an Indigenous people of the region where the species is endemic (Pérez-Farrera and colleagues, 2001, cited by the 2022 monograph; Haynes, 2022).

The species had been collected before its description: the monograph cites specimens from 1996 in the municipality of Solosuchiapa, and the original description a specimen collected by Breedlove in September 1981 (no. 52686, CAS). In 2001 the authors announced efforts to bring it into cultivation at the Clavijero Botanic Garden in Xalapa, at UNICACH and at the botanic garden of the Institute of Biology of the National Autonomous University of Mexico (UNAM); no published source documents the outcome.

Common names

No common name is recorded, in English or in any other language: the 2022 monograph lists none, and no Zoque name for the plant is documented.

In the wild

Ceratozamia zoquorum is endemic to the northern mountains of Chiapas according to the 2022 monograph. It grows on karst outcrops, in evergreen tropical forest and oak forest, between 500 and 1,150 m, with collections from the municipalities of Solosuchiapa, between about 500 and 680 m, and Tila, at 1,135 m. The World List of Cycads adds Tabasco to its range; this may reflect the period when Ceratozamia becerrae, which grows in Tabasco, was included in it, or the broader concept still used by the Red List, but no source states the reason.

The original description places the species in three-layered evergreen tropical forest, with a canopy of Brosimum alicastrum, Dialium guianense, Manilkara zapota and Calophyllum brasiliense and an understorey of Astrocaryum mexicanum and Chamaedorea palms, on karst cliffs; the soils of these mountains are calcareous rendzinas and red clays, on steep slopes (70%), between 520 and 1,200 m. The authors then knew only one population.

No study of pollination, germination or population dynamics has been published for the species.

Conservation status and regulation

Ceratozamia zoquorum is listed as Critically Endangered (CR) 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 differ between sources: The World List of Cycads gives A2acd, that is, a strong observed decline of the population linked to the reduction and degradation of its habitat and to exploitation; the 2022 monograph gives A2c+4c and B1ab(i,ii,iii,v). Because the Red List treats Ceratozamia becerrae as a synonym, this assessment also covers the plants of the Sierra Madrigal that The World List of Cycads, the WCVP and the monograph assign to that species. As early as 2001, the describers considered the species Critically Endangered under the 1994 criteria, as no other population was known, and feared its extinction if the destruction of the forests of northern Chiapas, converted to pasture and coffee plantations, continued.

In Mexico, the species is listed as “in danger of extinction” (P) in the standard NOM-059-SEMARNAT-2010, in the list as modified on 14 November 2019, which does not mark it as endemic; Ceratozamia becerrae appears there separately as “threatened” (A). Like the whole genus, it has been covered by CITES Appendix I since 1 August 1985 (cycads 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+ lists it under its own name (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.

In practice, buy only seed-grown plants with documents of origin. An old plant sold under this name may also be a Ceratozamia becerrae, which was included in it between 2017 and 2020. This general information does not replace the official texts: check the regulations in force before buying, importing or exchanging plants.

Growing Ceratozamia zoquorum

No source describes the cultivation of Ceratozamia zoquorum beyond the experimental cultivation reported by its describers. The pointers below are drawn from its habitat and from the general rules for the genus; they have not been confirmed by published trials.

  • Light: partial shade or light shade, as in tropical forest; avoid sudden full sun.
  • Soil: very free-draining, with a mineral fraction, recalling the limestone outcrops where it grows.
  • Watering: regular during growth, without standing water, reduced in winter.
  • Space: a medium-sized plant, suitable for a large pot.

Outdoor and in-ground cultivation

No outdoor planting of Ceratozamia zoquorum has been documented with a dated result. The American gardens that declare it, in California and Florida, do not say whether their plants grow outdoors or under glass.

Container cultivation

With its short trunk and few leaves, it can be grown in a large pot in a mineral, free-draining mix, which allows it to be moved under cover in winter.

In cultivation in the UK, US and Australia

In the United States, BGCI PlantSearch (queried on 30 October 2026) lists Ganna Walska Lotusland (Santa Barbara) and the Huntington (San Marino) in California, and Montgomery Botanical Center (Coral Gables, Florida); the online catalogue of Montgomery Botanical Center lists seven accessions. No garden in the United Kingdom or Australia declares it. Outside these countries, BGCI lists two gardens in Mexico: the Faustino Miranda Botanic Garden in Chiapas and the Francisco Javier Clavijero Botanic Garden in Xalapa. Plants received before 2020 under this name may include Ceratozamia becerrae. No garden states whether its plants grow outdoors.

Propagation

Propagation is from seed. The plants are male or female: both sexes and, in cultivation, hand pollination are needed to obtain fertile seed. No germination data specific to the species have been published. Handle seeds wearing gloves.

Pests and diseases

No pest or disease specific to Ceratozamia zoquorum 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 zoquorum: no dated cultivation report, and no temperature record published for its sites.

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. A plant of tropical forest at low and middle elevations, it is best kept frost-free, under glass or indoors in cold regions, until documented trials exist.

Toxicity and precautions

No toxicity study specific to Ceratozamia zoquorum 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 use is recorded: the 2022 monograph lists none, and the name of the species honours the Zoques without referring to any particular use.

Frequently asked questions

Where does the name zoquorum come from?

From the Zoque people. The Latin epithet means “of the Zoques” and honours the Indigenous culture of northern Chiapas, where the species is endemic.

Where does it grow?

In the northern mountains of Chiapas, Mexico. It lives on limestone outcrops in tropical forest and oak forest, between 500 and 1,150 m. The World List of Cycads also gives Tabasco.

What is the difference from Ceratozamia becerrae?

Very little to the naked eye. The two species were merged from 2017 to 2020, then separated on the basis of leaflet anatomy. Today DNA remains the most reliable way to tell them apart, and the IUCN Red List still treats them as one species.

How can I recognise it?

By its few broad leaflets. It has 6 to 17 pairs of oblong, leathery leaflets, 4 to 5.6 cm wide, and its young leaves have a pink petiole. The stalk of the female cone is longer than 3 cm, which separates it from Ceratozamia santillanii.

Is it endangered?

Yes, critically. The IUCN has listed it as Critically Endangered since 2022, and Mexico as in danger of extinction. Like the whole genus, it is in CITES Appendix I.

Can it take frost?

Nobody knows, and it is unlikely. No documented trial exists, and it is a plant of tropical forest: keep it frost-free.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Pérez-Farrera, M.A., Vovides, A.P. & Iglesias, C.G. (2001). A new species of Ceratozamia (Zamiaceae) from Chiapas, Mexico. Botanical Journal of the Linnean Society 137(1): 77–80. [Original description; primary source.]
  • Martínez-Domínguez, L., Nicolalde-Morejón, F., Vergara-Silva, F., Stevenson, D.W. & del Callejo, E. (2017). Cryptic diversity, sympatry, and other integrative taxonomy scenarios in the Mexican Ceratozamia miqueliana complex (Zamiaceae). Organisms Diversity & Evolution 17(4): 727–752. https://doi.org/10.1007/s13127-017-0341-7 [Synonymy of Ceratozamia becerrae, as reported by The World List of Cycads and the monograph.]
  • Vovides, A.P., Pérez-Farrera, M.A., Gutiérrez-Ortega, J.S., Avendaño, S., Medina-Villarreal, A., González-Astorga, J. & Galicia, S. (2020). A revision of the Ceratozamia miqueliana (Zamiaceae) species complex based on analyses of leaflet anatomical characters. Flora 270: 151649. https://doi.org/10.1016/j.flora.2020.151649 [Reinstatement of Ceratozamia becerrae; content cited from the 2022 monograph.]
  • 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.]
  • 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 [Unstable position in the phylogeny, evolution of the cones; open access.]
  • Bösenberg, J.D. (2022). Ceratozamia zoquorum. The IUCN Red List of Threatened Species 2022: e.T212187677A69867542. https://doi.org/10.2305/IUCN.UK.2022-1.RLTS.T212187677A69867542.en [Current assessment, Critically Endangered, under which the Red List places Ceratozamia becerrae; 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.]