Ceratozamia dominguezii

Ceratozamia dominguezii is a large cycad of south-eastern Mexico, known only from the lowland tropical forests on karst of Uxpanapa, in southern Veracruz, at 100 to 130 m (about 330 to 430 ft). Described in 2021, this species of the genus Ceratozamia stands out for its caramel-coloured young leaves, its very long leaves and the dark violet centre of its cone scales. Its status is disputed: the 2022 monograph of the genus placed it in synonymy under Ceratozamia subroseophylla, and the World Checklist of Vascular Plants (WCVP, the database behind POWO) follows that treatment, but The World List of Cycads rejects the synonymy and keeps it as a separate species. The Uxpanapa plants were long filed under Ceratozamia robusta.

Key facts about Ceratozamia dominguezii

  • Accepted name: Ceratozamia dominguezii Pérez-Farr. & Gut.Ortega (2021), accepted by The World List of Cycads (version 2026.08.15); treated as a synonym of Ceratozamia subroseophylla by the 2022 monograph and by the WCVP (read via GBIF), a synonymy rejected by The World List of Cycads and by Haynes (2023)
  • Former names and synonyms: no synonym; its populations were previously identified as Ceratozamia robusta
  • Family: Zamiaceae, order Cycadales
  • Common names: none recorded
  • Natural range: Mexico, south-eastern Veracruz (municipalities of Uxpanapa and Jesús Carranza), tropical forest on karst, 100 to 130 m
  • IUCN status: Not Evaluated (NE); Critically Endangered proposed by the authors of the description, Endangered in a preliminary assessment published in 2025
  • CITES and other protection: CITES Appendix I (whole genus, since 1985); Annex A in the European Union, seeds included
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: in the wild, the understorey of lowland tropical forest, on limestone rocks
  • Habit and adult size: trunk 32 to 132 cm tall and 20 to 30 cm across; 22 to 43 leaves, 1.65 to 3.16 m long
  • In the UK, US and Australia: no garden declares it
  • Toxicity: no data specific to the species; treat it as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Ceratozamia dominguezii

Three features together identify it: very long leaves with widely spaced leaflets, young leaves of a caramel colour, and cone scales whose outer face is dark violet in the centre. The original description (Pérez-Farrera and colleagues, 2021) gives the following measurements:

  • Trunk: cylindrical, upright, sometimes lying down with age, unbranched, covered with old leaf bases, 32 to 132 cm tall and 20.7 to 30 cm in diameter; the plant grows on rocks.
  • Leaves: 22 to 43 in a half-open crown, upright then ascending, 1.65 to 3.16 m long and 50 to 68 cm wide, caramel-coloured when they emerge, then green; petiole 35 to 103 cm, densely armed with thick prickles; rachis 1.02 to 2.48 m, with scattered prickles.
  • Leaflets: 15 to 37 pairs, papery, linear, slightly to clearly sickle-shaped, with entire margins; median leaflets 25 to 43 cm by 2.7 to 4.5 cm, spaced 2.7 to 6.2 cm apart, with 30 to 33 faint veins.
  • Male cones: solitary, conical, upright, 34 to 50 cm by 5 to 6 cm, with orange hairs when they emerge.
  • Female cones: solitary, cylindrical, upright, 44 to 48 cm by 10 to 12 cm, with a short point; scales two-horned, dark violet in the centre of the outer face, fading to yellowish brown towards the edges.
  • Seeds: egg-shaped, 2.5 to 2.9 cm long, with cream flesh before ripening.

Compared with the other species of the Ceratozamia robusta complex, the Uxpanapa plants have on average the longest rachis (about 1.73 m), the most widely spaced median leaflets and the widest basal leaflets. Their leaflets are papery, whereas they are leathery in Ceratozamia aurantiaca.

Hybrids

No natural or garden hybrid has been documented.

Possible confusion

Out of its habitat, it can be mistaken for the other large species of the Ceratozamia robusta complex, all with stout trunks, big leaves and very prickly petioles:

  • Ceratozamia subroseophylla, from the Sierra de Los Tuxtlas, has yellowish-brown young leaves, longer petioles, more leaflets and a pinkish base to the scales of the female cone;
  • Ceratozamia robusta, from Chiapas and Guatemala, has reddish-brown young leaves, a closed crown and a female cone with a drawn-out tip;
  • Ceratozamia aurantiaca, from northern Oaxaca, has orange young leaves and leathery leaflets.

Another species of the genus lives at Uxpanapa, Ceratozamia euryphyllidia, but it belongs to a different group and its very broad leaflets make it easy to tell apart. Without a known wild origin, a cultivated plant cannot be assigned with certainty to any of these species.

Taxonomy: a disputed species

Ceratozamia dominguezii is accepted by The World List of Cycads, but specialists openly disagree on its validity, and the main reference databases do not treat it in the same way.

The 2021 description

The Uxpanapa plants were first collected in 1975 by the botanist Mario Vázquez Torres, of the Universidad Veracruzana, and identified as Ceratozamia robusta. While revising this species complex, Miguel Angel Pérez-Farrera, José Said Gutiérrez-Ortega and their colleagues found the populations again in the wild in 2019, measured fifteen adult plants and compared their leaves with those of Ceratozamia robusta, Ceratozamia subroseophylla and Ceratozamia aurantiaca. Six of the seven characters measured differed significantly between species, and a discriminant analysis clearly separated the four groups. The species was described in the journal Taxonomy in 2021.

The 2022 synonymy

In their monograph of the genus (PhytoKeys, 2022), Lilí Martínez-Domínguez and her co-authors placed the Uxpanapa populations under Ceratozamia subroseophylla, a species they had described in 2016 from the Los Tuxtlas populations. In their view, these plants “fall within the range of variation” of Ceratozamia subroseophylla as they define it, on the basis of leaf and cone morphology and phenology; their description of that species includes specimens from Uxpanapa and Jesús Carranza.

The position of The World List of Cycads and of the WCVP

The World List of Cycads explicitly rejects this synonymy. Its note states that the monograph placed the species under Ceratozamia subroseophylla without addressing the morphometric and qualitative differences set out in the 2021 description, and without providing data to support the change; the synonymy is therefore rejected “until convincing evidence is published”. Jody Haynes, in a critical review of the monograph published in Phytotaxa in 2023, also rejects it.

The WCVP, consulted through GBIF on 30 October 2026, follows the monograph: it lists Ceratozamia dominguezii (Taxonomy 1: 353, 2021) as a synonym of Ceratozamia subroseophylla. In practice, the same plant may therefore appear under either name depending on the source. This site follows The World List of Cycads, the checklist of the IUCN Cycad Specialist Group. No genetic study can settle the question yet: a 2025 assessment notes that no sequence of the species is available in GenBank.

Etymology and history

The epithet honours Héctor Gómez-Domínguez, a retired technician of the Eizi Matuda herbarium in Chiapas, whose field explorations and collections led to the discovery of several new cycads in southern Mexico (Haynes, 2022, as quoted by The World List of Cycads).

The type specimen, a male plant, was collected on 29 May 2021 in the municipality of Uxpanapa, at 130 m, by Miguel Angel Pérez-Farrera (number 4013); the holotype is kept in the HEM herbarium, with isotypes at MEXU and XAL. The name was published the same year in Taxonomy (volume 1, issue 4).

Common names

No vernacular name is known, in English, Spanish or any local language; the plant is simply called Ceratozamia dominguezii.

In the wild

Ceratozamia dominguezii grows only in the Uxpanapa floristic refuge, in south-eastern Veracruz. It lives on rocks in tropical forest on karst, between 100 and 130 m. The original description lists among its companion plants Brosimum alicastrum, Swietenia macrophylla, Bursera simaruba, Pseudobombax ellipticum, the palm Astrocaryum mexicanum and several Chamaedorea.

According to the authors, the Uxpanapa refuge is thought to have sheltered many tropical plants during the climatic fluctuations of the Neogene, which would explain the divergence of the species. Uxpanapa is home to two other cycads, Ceratozamia euryphyllidia and Zamia purpurea. Four populations were known in 2021; the 2025 assessment counts five, in three municipalities.

Conservation status and regulation

Ceratozamia dominguezii has not been assessed on the IUCN Red List (Not Evaluated, according to The World List of Cycads and to the Red List data relayed by GBIF, checked on 30 October 2026), but every proposed assessment considers it highly threatened:

  • in 2021, the authors of the description proposed Critically Endangered (CR, criterion B2ab(i,ii,iii,iv,v)), because of the deforestation of Uxpanapa, one of the most affected forests of Veracruz;
  • in 2025, in a study of the cycads of Veracruz published in Cambridge Prisms: Extinction, Jorge Antonio Gómez Díaz proposed, as a preliminary assessment, Endangered, and category P (“in danger of extinction”) under the method of the Mexican standard NOM-059. He estimated its extent of occurrence at 1,318 km² (about 509 square miles), with 87% of the habitat transformed and no part in a protected area; the species had one of the highest priority scores among the cycads of the state, and the lowest level of knowledge.

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+ does not list this name, but the listing covers the entire genus, seeds included (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 dominguezii

No source documents the cultivation of Ceratozamia dominguezii, and no grower has reported on it. The only useful pointers come from its habitat: warm, humid lowland tropical forest, a shaded understorey and well-drained limestone rocks. The general advice given for the genus (partial shade, free-draining substrate, regular watering without excess) applies with that reservation.

Outdoor and in-ground cultivation

No outdoor planting has been documented anywhere outside its habitat. Only frost-free tropical or warm subtropical gardens, with shade and a fast-draining, stony soil, would come close to its natural conditions; this is inferred, not tested.

Container cultivation

No container-growing report exists. Its leaves, which can exceed 3 m, would make it a large plant for a heated glasshouse; a free-draining mix with limestone grit, bright shade and steady warmth would match its habitat.

In cultivation in the UK, US and Australia

No garden in the United Kingdom, the United States or Australia declares Ceratozamia dominguezii to BGCI PlantSearch, and the name does not appear in the living collection of Montgomery Botanical Center (both checked on 30 October 2026). Plants from Uxpanapa grown before 2021 may carry the name Ceratozamia robusta or, since 2022, Ceratozamia subroseophylla.

Propagation

No data specific to the species. Like the other Ceratozamia, it has separate male and female plants and can realistically only be propagated from fertilised seed. Nothing has been published on the germination or growth of its seedlings.

Pests and diseases

No pest or disease has been documented for this species.

Cold hardiness

Nothing is known about its tolerance of cold, heat or drought. Its habitat, at 100 to 130 m in southern Veracruz, is one of the warmest in the genus: nothing suggests any tolerance of frost.

Mediterranean and European experience

No cultivation has been reported in France or Italy, in the ground or in a pot, and the Jardin zoologique tropical in La Londe-les-Maures (Var, on the French Riviera) has published no observation of it. In Mediterranean-type climates such as California or southern Australia, it should be treated as a frost-tender plant.

United Kingdom, United States and Australia

No cold record and no commercial hardiness rating have been published. In the UK it would need a heated glasshouse.

Toxicity and precautions

No toxicity data exist for the species or the genus. The risk is documented in other cycads: their seeds and leaves contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, a compound harmful to the liver and nervous system. Treat the plant as poisonous to people and animals, wear gloves to handle the seeds, and if any part is swallowed, call a poison centre, a doctor or a vet straight away.

Traditional uses

No use has been documented for this species.

Frequently asked questions

Is Ceratozamia dominguezii a valid species?

It depends on the source. The World List of Cycads accepts it and rejects its synonymy for lack of published evidence; the 2022 monograph and the WCVP, the database behind POWO, place it under Ceratozamia subroseophylla. This site follows The World List of Cycads.

Where does it grow?

Only at Uxpanapa, in south-eastern Veracruz, Mexico, in tropical forest on karst between 100 and 130 m.

How can it be recognised?

By its caramel-coloured young leaves, its very long leaves (over 3 m) with widely spaced leaflets, and the dark violet centre of the scales of both male and female cones.

Is it endangered?

Very probably. The IUCN has not assessed it yet, but its describers proposed Critically Endangered, and a preliminary 2025 assessment ranks it Endangered, with 87% of its habitat already transformed.

Is it cold-hardy?

Nobody knows, and it is unlikely. No trial or growing report exists, and it lives in one of the warmest parts of the genus’s range, at low altitude: treat it as a frost-free plant.

Can it be bought?

Only as an artificially propagated plant with its documents. The whole genus is in CITES Appendix I and Annex A of the EU regulation, and no commercial offer of this species has been documented.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Pérez-Farrera, M.A., Gutiérrez-Ortega, J.S., Vovides, A.P., Calonje, M. & Díaz-Jiménez, P. (2021). Ceratozamia dominguezii (Zamiaceae): a new cycad species from southeastern Mexico. Taxonomy 1(4): 345–359. https://doi.org/10.3390/taxonomy1040026 [Original description: morphometrics, habitat, type, proposed status; open access. 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 [Synonymy under Ceratozamia subroseophylla; open access.]
  • Haynes, J.L. (2023). Critical review of “Monograph of Ceratozamia (Zamiaceae, Cycadales): an endangered genus” published in PhytoKeys 208: 1–102 (2022). Phytotaxa 612(2): 159–200. https://doi.org/10.11646/phytotaxa.612.2.4 [Rejection of the synonymy; abstract.]
  • Gómez Díaz, J.A. (2025). Assessing the extinction risk of Veracruz cycads. Cambridge Prisms: Extinction 3: e7. https://doi.org/10.1017/ext.2025.5 [Preliminary assessment and threat indicators; open access.]
  • 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.]