Ceratozamia delucana

Ceratozamia delucana is a large cycad of east-central Mexico, found in the Sierra Norte de Puebla and central Veracruz, in evergreen tropical forest and cloud forest between 500 and 1,650 m (about 1,650 to 5,400 ft). Described in 2013, this species of the genus Ceratozamia can carry up to a hundred leaves more than 2 m long. Highly variable, it is told apart from its neighbours mainly by its female cones, green and almost hairless when mature according to the 2022 monograph, but brown according to the original description. The IUCN Red List assesses it as Endangered.

Key facts about Ceratozamia delucana

  • Accepted name: Ceratozamia delucana Vázq.Torres, A.Moretti & Carvajal-Hern. (2013), 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
  • Natural range: Mexico, northern Puebla and central Veracruz, 500 to 1,650 m
  • IUCN status: Endangered (EN, criteria A2cd; B1ab(i,ii,iii)), assessment published in 2022
  • CITES and other protection: CITES Appendix I (whole genus, since 1985); Annex A in the European Union
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: in the wild, limestone rocks in evergreen tropical forest and mountain cloud forest according to the monograph; sandy hills rich in organic matter according to the original description
  • Habit and adult size: trunk 20 to 90 cm long and 25 to 40 cm across, with 10 to 100 leaves 1.06 to 2.23 m long (monograph); a half-buried trunk under 20 cm tall with more than 30 leaves 1.5 to 2 m long (original description)
  • In the UK, US and Australia: San Diego Botanic Garden (California); none in the UK or Australia
  • Toxicity: no data specific to the species; treat it as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Ceratozamia delucana

It is a large, very variable plant, with a thick trunk and many leaves, whose leaflets are often glaucous. According to the monograph, the most reliable character is the female cone: green, usually hairless when mature, with an acute tip; the original description, however, calls it brown when mature, with a mucronate tip (see below). The 2022 monograph by Martínez-Domínguez and colleagues describes it as follows:

  • Trunk: above ground, upright or decumbent, 20 to 90 cm long and 25 to 40 cm across.
  • Leaves: 10 to 100, ascending, 106 to 223 cm long, yellowish green with brown hairs when they emerge; petiole 30 to 87 cm, light green, with 35 to 76 thin prickles; rachis prickly.
  • Leaflets: 20 to 43 pairs, lanceolate to oblong, papery to leathery, glaucous; median leaflets 22 to 45 cm by 2.3 to 4.6 cm; articulation green.
  • Male cones: cylindrical, upright, 24 to 32 cm by 5.5 to 7.6 cm, greenish yellow with blackish hairs.
  • Female cones: cylindrical to globose, 17 to 40 cm by 10 to 13.5 cm, dark green with blackish hairs when they emerge, green and usually hairless when mature, with an acute tip; 48 to 266 scales.
  • Seeds: oval, 2 to 3 cm, with yellow flesh turning light brown.

The monograph and a 2024 study of the evolution of reproductive characters stress its polymorphism: the shape and symmetry of the leaflets and the shape of the female cone and male scales vary from plant to plant. In the identification key of the monograph, the species appears in four different places, a sign of this variability.

The original description (Vázquez-Torres, Moretti and Carvajal-Hernández, 2013), now available online from the Orto Botanico di Napoli, does not agree in every respect with the monograph. It describes a half-buried trunk, less than 20 cm tall and 30 to 40 cm across; more than 30 leaves 1.5 to 2 m long, with a petiole 50 to 90 cm long armed with stout prickles; 50 to 70 leaflets on each side (the monograph counts 20 to 43 pairs), papery, 30 to 45 cm by 2 to 4 cm; male cones 20 to 40 cm by 6 to 7 cm, greenish white turning yellowish white; a female cone greenish when young and brown to dark brown when mature, 13 to 22 cm by 6 to 8 cm, with a mucronate tip, on a felted peduncle 10 to 18 cm long; and seeds 2.1 to 2.4 cm long. Until the two sources are reconciled, the colour of the mature female cone cannot be used as a reliable character.

Hybrids

No natural or garden hybrid has been documented.

Possible confusion

Ceratozamia delucana belongs to the Ceratozamia mexicana complex and resembles two neighbouring species above all:

  • Ceratozamia morettii, from the cloud forest of Veracruz, has similar foliage, but it is a smaller plant, with a female cone that is green and covered in blackish hairs when mature, with an apiculate tip;
  • Ceratozamia totonacorum, from the Sierra Norte de Puebla, differs in its brown young leaves;
  • Ceratozamia mexicana and Ceratozamia tenuis, from central Veracruz, belong to the same complex.

The authors of the original description considered it closest to Ceratozamia latifolia, which has leaflets of similar shape but a much smaller trunk, leaves and leaflets; they placed it in the broad-leaved group of central-eastern Mexico, with Ceratozamia latifolia, Ceratozamia mexicana and Ceratozamia morettii, none of which grows alongside it. Away from its habitat, a plant of unknown origin is hard to assign with certainty.

Taxonomy

Ceratozamia delucana was described by Mario Vázquez Torres, Aldo Moretti and Carlos Carvajal-Hernández in Delpinoa, the journal of the Orto Botanico di Napoli (volume 50–51, dated 2008–2009 but issued in December 2013); The World List of Cycads and the WCVP give 2013 as the year of publication. Its name has not changed since.

Two recent studies support its status. The phylogenomic study by Habib and colleagues (2023), which sampled it, places it in the latifolia subclade of the Mexicana clade, with Ceratozamia mexicana, Ceratozamia tenuis, Ceratozamia morettii, Ceratozamia fuscoviridis and Ceratozamia totonacorum. In 2025, the integrative study by Medina-Villarreal and colleagues, combining phylogeography, morphometrics and climatic niches, recognised it as one of the seven distinct lineages of the Ceratozamia mexicana complex.

Etymology and history

The epithet honours Paolo De Luca (1944–2021), professor at the University of Naples Federico II, described in the original description as an indefatigable researcher in biology and a promoter of the study of Mexican cycads since 1970.

The type specimen, a female plant, was collected on 20 January 2012 by Mario Vázquez Torres and Carlos Carvajal-Hernández (number 10200) in the municipality of Atzalan (Veracruz), in mountain cloud forest at about 1,400 to 1,500 m. The holotype is kept in the CIB herbarium, with isotypes at XAL and XALU. The original description deliberately leaves out the precise locality to protect the populations from commercial collectors. Much older collections, now referred to this species, exist: 1970 at Tlapacoyan and 1979 at Las Minas.

Common names

No vernacular name is known; the 2022 monograph records none, and there is no English name.

In the wild

Ceratozamia delucana grows in northern Puebla (municipalities of Hueytamalco and Xochitlán de Vicente Suárez) and central Veracruz (Atzalan, Las Minas, Tlapacoyan). According to the monograph, it grows on karst limestone rocks in evergreen tropical forest, between 500 and 1,650 m; the type locality is recorded in mountain cloud forest. The WCVP gives its range as central Mexico and the Mexican Gulf region. The authors of the monograph monitored six populations for six years: they recorded no loss of individuals, observed regeneration and regular production of male and female cones.

The original description paints a somewhat different picture: the species grows mainly on low, more or less consolidated sandy hills with slopes of 30 to 50°, covered with abundant organic matter, in mountain cloud forest with Pinus pseudostrobus, Pinus chiapensis, Clethra mexicana, Alnus jorullensis, Quercus crassifolia, Liquidambar macrophylla and tree ferns, slightly disturbed by goat and sheep grazing and marginal farming. The authors had seen only three groups, totalling fewer than 300 adult plants. The two descriptions of the habitat (limestone rocks or sandy hills) have not been reconciled to date.

Conservation status and regulation

Ceratozamia delucana is assessed as Endangered (EN, criteria A2cd; B1ab(i,ii,iii)) on the IUCN Red List, in the assessment by J.D. Bösenberg, L. Martínez-Domínguez and F. Nicolalde-Morejón published in 2022. The category is given by The World List of Cycads and confirmed by the Red List data relayed by GBIF (checked on 30 October 2026). The main threat is habitat loss in central Veracruz, where no protected area covers the species.

The 2025 assessment of the cycads of Veracruz (Gómez Díaz) gives it five localities, an extent of occurrence of 1,050 km² (about 405 square miles), 45% of its habitat lost and no population in a protected area; applying the method of the Mexican standard NOM-059, the author proposes category A (“threatened”), as the species is not yet on that list.

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 separately, but the listing covers the whole 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 delucana

No growing guide and no grower’s report have been published for Ceratozamia delucana. Its habitat, under forest cover from tropical forest to cloud forest, on limestone rocks according to the monograph or on sandy hills rich in organic matter according to the original description, suggests a plant for partial shade in a free-draining, humus-rich substrate with steady moisture; this advice is deduced from the habitat, not from cultivation results.

Outdoor and in-ground cultivation

No outdoor planting has been documented. In frost-free gardens with mild, humid winters, a lightly shaded spot in well-drained, humus-rich soil would match its habitat; this is inferred, not tested.

Container cultivation

No container-growing report has been published. A large plant with many long leaves, it needs a big container, a free-draining but humus-rich compost and a frost-free glasshouse or conservatory in winter outside frost-free climates.

In cultivation in the UK, US and Australia

In the United States, San Diego Botanic Garden (Encinitas, California) declares the species to BGCI PlantSearch; it is the only holder declared worldwide. The species does not appear in the online catalogue of Montgomery Botanical Center, and no garden in the UK or Australia declares it (BGCI and Montgomery checked on 30 October 2026). A BGCI listing shows that a garden has declared the species at some point, not that a living plant is there today.

Propagation

No data specific to the species. Like all Ceratozamia, it has separate male and female plants and is propagated from fertilised seed; its female cones can carry more than 250 scales.

Pests and diseases

No pest or disease has been documented for this species.

Cold hardiness

There are no data on the cold tolerance of Ceratozamia delucana. Its highest sites, at about 1,600 m in cloud forest, are among the coolest in the genus, but no minimum temperature has been published for them and no trial exists.

Mediterranean and European experience

No cultivation has been reported in France or Italy, in the ground or in a pot. At the Jardin zoologique tropical in La Londe-les-Maures (Var, on the French Riviera), no observation of it has been published. In Mediterranean-type climates such as California or southern Australia, it should be protected from frost until its tolerance is known.

United Kingdom, United States and Australia

No cold record and no commercial hardiness rating have been published. San Diego Botanic Garden does not state its growing conditions; in the UK it would need a frost-free glasshouse.

Toxicity and precautions

No toxicity data concern the species or the genus. In the cycads studied, 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 pets; if any part is swallowed, call a poison centre, a doctor or a vet straight away.

Traditional uses

No use has been documented; the 2022 monograph records none.

Frequently asked questions

Where does Ceratozamia delucana grow?

In northern Puebla and central Veracruz, Mexico, between 500 and 1,650 m, on limestone rocks according to the monograph and on sandy hills according to the original description.

How does it differ from Ceratozamia morettii?

By its size and its cones. Ceratozamia delucana is larger, with leaves up to 2.2 m long and many leaflets (20 to 43 pairs according to the monograph, 50 to 70 on each side according to the original description). According to the monograph, its female cone is green and almost hairless when mature, with an acute tip; the original description, however, calls it brown when mature.

Who was De Luca?

Paolo De Luca (1944–2021), professor at the University of Naples Federico II, a specialist in the biology of Mexican cycads who had promoted their study since 1970, according to the original description.

Is it endangered?

Yes. It has been assessed as Endangered by the IUCN since 2022, because of the loss of its habitat in central Veracruz, where no reserve protects it.

Is it cold-hardy?

Nobody knows. No trial or cultivation report has been published, even though some of its sites are in cloud forest at about 1,600 m.

Is it part of the Ceratozamia mexicana complex?

Yes. A 2025 study recognises it as one of the seven distinct lineages of this complex, alongside Ceratozamia mexicana, Ceratozamia tenuis and Ceratozamia morettii.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Vázquez-Torres, M., Moretti, A. & Carvajal-Hernández, C. (2013). A new species of Ceratozamia (Zamiaceae) from Veracruz, Mexico. Delpinoa 50–51: 129–133 (dated 2008–2009, issued December 2013). [Original description: diagnosis, description, habitat, type, etymology, comparison with related species. 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 [Description, range, population monitoring; 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 [Phylogenetic position; 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 [Polymorphism.]
  • Medina-Villarreal, A., González-Astorga, J. & Espinosa de los Monteros, A. (2025). Integrative taxonomy of the Ceratozamia mexicana Brongn. (Zamiaceae) species complex from a phylogeographic perspective. Plant Species Biology 40(6): 530–546. https://doi.org/10.1111/1442-1984.70008 [Seven lineages of the complex; 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 [Localities, habitat loss, proposed NOM-059 category; open access.]
  • Bösenberg, J.D., Martínez-Domínguez, L. & Nicolalde-Morejón, F. (2022). Ceratozamia delucana. The IUCN Red List of Threatened Species 2022: e.T66901148A66901156. https://doi.org/10.2305/IUCN.UK.2022-1.RLTS.T66901148A66901156.en [Current assessment, Endangered; category given by The World List of Cycads and GBIF, reference found on Crossref.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. https://doi.org/10.11646/phytotaxa.550.1.1 [Etymology given by The World List of Cycads, with the dates of Paolo De Luca.]
  • 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.]