Ceratozamia santillanii

Ceratozamia santillanii is a small cycad of Mexico, known from a single locality in the northern highlands of Chiapas, in the municipality of Berriozábal, where it grows on limestone rocks in tropical rainforest between 800 and 900 m (about 2,620 to 2,950 ft). This species of the genus Ceratozamia, described in 2009, is one of the smallest in the genus according to the 2022 monograph: two or three leaves under 80 cm long (its original description gave it 4 to 7, up to 2.1 m), set with a few broad, leathery leaflets. It is listed as Critically Endangered by the IUCN. Two beetles new to science have been described from its male cones.

Key facts about Ceratozamia santillanii

  • Accepted name: Ceratozamia santillanii Pérez-Farr. & Vovides (2009), 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, northern highlands of Chiapas, known only from the type locality (municipality of Berriozábal), 800 to 900 m
  • IUCN status: Critically Endangered (CR), 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 frost records (see Cold hardiness)
  • Light and soil: in the wild, limestone (karst) rocks in evergreen tropical rainforest; no published growing advice
  • Habit and adult size: trunk 10 to 50 cm long and 11 to 13 cm across, partly buried; 2 or 3 leaves 50 to 80 cm long (2022 monograph); the original description (2009) gives a trunk 20 to 67 cm long and 4 to 7 leaves 0.6 to 2.1 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 santillanii

According to the 2022 monograph, it is a dwarf plant with very few leaves (the original description describes a much larger plant, see below), each carrying only 6 to 12 pairs of broad, oblong, leathery leaflets with a drawn-out, asymmetrical tip. The short stalk (peduncle) of its female cone, 3 cm long at most, is the character that best separates it from its two sister species. The 2022 monograph describes it as follows:

  • Trunk: 10 to 50 cm long and 11 to 13 cm across, half buried, upright then lying down; cataphylls reddish brown, covered in brown down when they emerge.
  • Leaves: 2 or 3, 50 to 79 cm long, drooping; light green with a bluish bloom when they emerge, covered in whitish-grey hairs, then green and hairless. Petiole 23 to 45 cm long, unarmed or carrying 4 to 15 slender prickles under 2 mm long.
  • Leaflets: 6 to 12 pairs, oblong, leathery, bluish-green on both sides, with a drawn-out, asymmetrical tip; the middle ones measure 17 to 31 cm by 4.2 to 6.5 cm and are spaced 3.5 to 7 cm apart; yellow points of attachment.
  • Male cones: solitary, cylindrical, upright, 15 to 20 cm long and 1.5 to 3 cm across, green with blackish hairs, then creamy yellow; peduncle 2 to 4 cm long.
  • Female cones: solitary, upright, 12 to 20 cm long and 7 to 9 cm across, green with blackish hairs; short peduncle, 2 to 3 cm long; scales with straight horns 6 to 8 mm long.
  • Seeds: oval, 2.2 to 2.4 cm long, with pinkish-white flesh turning light brown.

The original description (Pérez-Farrera and colleagues, 2009), based on twelve adult plants of the wild population and on plants grown for four years in a greenhouse, gives much larger figures for the vegetative parts: a rock-dwelling, cylindrical trunk, upright or arching, underground or partly so, 20 to 67 cm long and 7.6 to 12.4 cm across; 4 to 7 drooping to lying leaves, olive green and coiled when they emerge, 62 to 211 cm long, covered when young in a light reddish-brown waxy bloom, then dark green and hairless; an upright petiole 25 to 115 cm long, unarmed or with a few stout prickles; 6 to 13 pairs of flat, leathery leaflets, 18.5 to 31.5 cm by 3.3 to 5.5 cm, with 32 to 39 veins invisible on the underside and a yellow to orange-green point of attachment; a conical male cone 20 to 22 cm long on a 3 to 4 cm peduncle; a cylindrical or barrel-shaped female cone 13 to 20 cm long and 8 to 9.2 cm across, on a slightly white-tomentose peduncle 2 to 3 cm long; and angular-ovate seeds 2.2 to 2.4 cm long. It also reports 2n = 16 chromosomes. The clearest difference from the monograph concerns the leaves: 4 to 7 leaves up to 2.1 m long, against 2 or 3 leaves under 80 cm. The monograph does not discuss this gap.

Hybrids

No natural or garden hybrid has been documented.

Possible confusion

Ceratozamia santillanii belongs to a group of so-called cryptic species, almost impossible to tell apart by eye: all have oblong, leathery leaflets with an asymmetrical tip, and they live in the same mountains of southern Mexico (Martínez-Domínguez and colleagues, 2022).

  • Ceratozamia zoquorum, of northern Chiapas: often a larger plant (up to 17 leaves more than 2 m long); above all, the peduncle of the female cone is longer than 3 cm. The 2009 key also separates it by visible veins, leaflets set closer together (1.7 to 2.4 cm apart, against 3.4 to 7.5 cm) and female cones that lean over at maturity.
  • Ceratozamia becerrae, of the border between Chiapas and Tabasco: also very close; according to the monograph, it can be separated reliably from Ceratozamia santillanii only by DNA. The original description of Ceratozamia santillanii nevertheless noted visible differences: slightly sickle-shaped, oblong to broadly oblanceolate leaflets in Ceratozamia becerrae, against oblanceolate leaflets that are not sickle-shaped in Ceratozamia santillanii.

The three species can be told apart by a region of nuclear ribosomal DNA, the ITS (Martínez-Domínguez and colleagues, 2017, cited by the monograph). For a plant without cones or provenance, identification is therefore unreliable. Without cones, a young Ceratozamia can also be mistaken for a Zamia.

Taxonomy

Ceratozamia santillanii 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; it has no synonym.

It was described in 2009 by Miguel Ángel Pérez-Farrera, Andrew Vovides and their co-authors in the journal Systematics and Biodiversity, as part of a reassessment of the Ceratozamia miqueliana complex, a group of species of south-eastern Mexico with broad leaflets. The authors measured adult plants of the five species of the complex (Ceratozamia becerrae, Ceratozamia euryphyllidia, Ceratozamia miqueliana, Ceratozamia zoquorum and the new species) and compared their measurements by discriminant analysis: the five species were separated, Ceratozamia santillanii being the most distinct of all, while Ceratozamia becerrae and Ceratozamia zoquorum were the closest. They placed it near Ceratozamia zoquorum (drooping leaves, leathery leaflets with a bloom, yellow-orange points of attachment), from which it differs in its female cone, upright at maturity, its veins invisible on the underside and its more widely spaced leaflets. To rule out an effect of the environment, plants were grown for four years under uniform conditions, at the school of biology of the University of Sciences and Arts of Chiapas (UNICACH) and at the Francisco Javier Clavijero Botanic Garden in Xalapa.

Its place in the genus remains debated. In a 2024 study of the evolution of cone characters, Ceratozamia santillanii groups with Ceratozamia norstogii and Ceratozamia alvarezii in the parsimony trees, but falls in different clades with the maximum likelihood method. The same study counts it among the species whose female cone has become smaller in the course of evolution (Martínez-Domínguez and colleagues, 2024).

Etymology and history

The epithet honours Trinidad Alemán Santillán, professor of botany and ecology at the University of Sciences and Arts of Chiapas (UNICACH), for his work in training young biologists (Pérez-Farrera and colleagues, 2009; Haynes, 2022, cited by The World List of Cycads).

The type is a female plant collected on 15 October 2004 by Miguel Ángel Pérez-Farrera (no. 3030) in the municipality of Berriozábal; the holotype is kept at the HEM herbarium in Tuxtla Gutiérrez, with isotypes at XAL and MEXU. A male specimen collected the same day (Pérez-Farrera 2944) is the paratype. The original description deliberately leaves out the precise locality to discourage illegal collecting; the municipality is given by the 2022 monograph. Apart from the plants grown for the 2009 study, no source documents the history of the species in cultivation.

Common names

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

In the wild

Ceratozamia santillanii is endemic to the northern highlands of Chiapas. It is known only from its type locality, in the municipality of Berriozábal, where it grows on karst rocks in evergreen tropical rainforest between 800 and 900 m (Martínez-Domínguez and colleagues, 2022). The monograph cites only one other specimen, collected the same day at the same place.

The original description details the habitat: the plants grow on the walls of “cimas”, holes in the limestone about 10 m across, in a three-layered lower montane rainforest (emergent trees 20 to 30 m tall such as Zanthoxylum culantrillo and Pseudolmedia oxyphyllaria; a lower layer with the palm Astrocaryum mexicanum, among others). The relief is rugged, with slopes of up to 80% and cliff faces, on karst with a shallow tropical rendzina soil. For the region, the authors give an average annual temperature of 23.9 °C (75 °F), minimum temperatures of 21.2 to 21.7 °C (70 to 71 °F) in December and January, maximum temperatures of 25.2 to 26 °C (77 to 79 °F) from April to June, and annual rainfall of 818 mm. They knew of a single population, in an area adjacent to the Selva Zoque region.

Beetles in its cones

In 2022, William Tang and Héctor Gómez Domínguez described in the journal Zootaxa two beetles new to science, of the family Erotylidae, Pharaxonotha perezi and Ceratophila chipjonesi, found in the male cones of Ceratozamia santillanii. Their descriptions, based on adults collected from a single male cone in May 2021, say nothing about their diet or about pollen being carried to female cones: their role as pollinators has not been demonstrated. In that cone, Ceratophila chipjonesi made up 70% of the adults of these beetles, Pharaxonotha perezi 25%, and a third, undescribed Pharaxonotha 5%. Other beetles of this group are described as pollinators of American cycads, such as Pharaxonotha portophylla on a Zamia of Puerto Rico (Franz and Skelley, 2008, cited by the article); attributing this role to the beetles of Ceratozamia santillanii remains an analogy.

Conservation status and regulation

Ceratozamia santillanii is listed as Critically Endangered (CR) on the IUCN Red List, under criteria A3cd+4cd and B1ab(i,ii,iii,iv,v), in an assessment by Andrew Vovides and Miguel Ángel Pérez-Farrera published in 2022 (status given by The World List of Cycads and confirmed by the Red List data distributed through GBIF, 30 October 2026). These criteria reflect a tiny, declining range and an expected fall in population. The 2022 monograph reached the same conclusion. With a single known locality, the species is highly vulnerable to clearing or collecting. As early as 2009, the authors of the description proposed the category Critically Endangered (CR B1), because of the small size of the only population and the rapid conversion of its habitat into pasture and coffee plantations.

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+ 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, the species is almost impossible to find in the trade. A plant offered under this name should come from seed raised in cultivation, with documents of origin; any plant taken from the wild directly threatens the only known population. This general information does not replace the official texts: check the regulations in force before buying, importing or exchanging plants.

Growing Ceratozamia santillanii

No source describes the cultivation of this species, and no cultivation report has been documented. The only plants known to have been grown are those raised for four years at UNICACH and at the Clavijero Botanic Garden for the 2009 study. 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: light or partial shade, as in the understorey of tropical forest.
  • Soil: very free-draining and mineral, with some limestone gravel to recall the karst rocks where it grows, and humus on the surface.
  • Watering: regular during growth, never leaving water standing, reduced in winter.
  • Growth: its few leaves are slow to be replaced; handle it with care.

Outdoor and in-ground cultivation

No outdoor planting of this species has been documented anywhere.

Container cultivation

Its small size makes it a natural pot plant, in a very free-draining mineral mix, kept warm and frost-free.

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).

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. Handle seeds wearing gloves.

Pests and diseases

No pest or disease specific to Ceratozamia santillanii has been documented. The beetles of its cones are not pests: they live in the male cones of the wild plant. 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 santillanii: no cultivation report, and no published frost record. The only temperatures available are regional averages from its original description, with minimum temperatures of about 21 °C (70 °F) in the coolest months.

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 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 santillanii 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 known: the 2022 monograph records none for this species.

Frequently asked questions

Where does Ceratozamia santillanii grow?

In a single known place, in the northern highlands of Chiapas, Mexico. It lives on limestone rocks in tropical rainforest, between 800 and 900 m, in the municipality of Berriozábal.

Is it endangered?

Yes, critically. The IUCN has listed it as Critically Endangered since 2022, because it is known from only one locality. Like the whole genus, it is listed in CITES Appendix I.

How can I recognise it?

By its small size and its few broad leaflets. According to the 2022 monograph, it carries only 2 or 3 leaves under 80 cm long (4 to 7 leaves up to 2.1 m according to the original description), with 6 to 12 pairs of leathery leaflets. The short peduncle of its female cone, 3 cm at most, separates it from Ceratozamia zoquorum.

What pollinates its cones?

Probably beetles, as in other American cycads. Two new species, Pharaxonotha perezi and Ceratophila chipjonesi, were described in 2022 from its male cones. Their descriptions do not mention pollination: this role remains assumed, by analogy with other American cycads.

Where does its name come from?

From a professor of botany in Chiapas. The epithet honours Trinidad Alemán Santillán, who taught at the University of Sciences and Arts of Chiapas.

Can it take frost?

Nobody knows, and it seems 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., Martínez-Camilo, R., Martínez-Meléndez, N. & Iglesias, C. (2009). A reassessment of the Ceratozamia miqueliana species complex (Zamiaceae) of southeastern Mexico, with comments on species relationships. Systematics and Biodiversity 7(4): 433–443. https://doi.org/10.1017/S1477200009990211 [Original description, type, habitat and climate, key, morphometric analysis, proposed status. Primary source.]
  • 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 [Position in the phylogeny, evolution of cones; open access.]
  • Tang, W. & Gómez Domínguez, H. (2022). Two new species of Pharaxonothinae beetles (Coleoptera: Erotylidae) inhabiting cones of the cycad Ceratozamia santillanii Pérez-Farr. & Vovides (Cycadales: Zamiaceae) in Mexico. Zootaxa 5150(3): 428–442. https://doi.org/10.11646/zootaxa.5150.3.7 [Beetles of the male cones; descriptions of the two species in open access.]
  • Vovides, A.P. & Pérez-Farrera, M.A. (2022). Ceratozamia santillanii. The IUCN Red List of Threatened Species 2022: e.T187829A1828396. https://doi.org/10.2305/IUCN.UK.2022-1.RLTS.T187829A1828396.en [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.]