Ceratozamia decumbens

Ceratozamia decumbens is a small cycad of central Veracruz, Mexico, that grows on limestone rocks in the lower mountain tropical forests and cloud forests around Córdoba, between 450 and 1,100 m (about 1,500 to 3,600 ft). Described in 2008, this species of the genus Ceratozamia takes its name from its trunk, which lies down with age. It carries few leaves with broad leaflets, and its small female cones are wine red. The IUCN Red List assesses it as Endangered. It should not be confused with Zamia decumbens, a different cycad from Belize.

Key facts about Ceratozamia decumbens

  • Accepted name: Ceratozamia decumbens Vovides, Avendaño, Pérez-Farr. & Gonz.-Astorga (2008), 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, central Veracruz (around Córdoba: Naranjal, Tequila, Zongolica and neighbouring municipalities), 450 to 1,100 m
  • IUCN status: Endangered (EN, criteria A2c; B1ab(i,ii,iii,v)), assessment published in 2022
  • CITES and other protection: CITES Appendix I (whole genus, since 1985); Annex A in the European Union
  • Documented hardiness: no cultivation report; at the type locality, the extreme minimums of the coldest month are 12 to 13 °C (53.6 to 55.4 °F) (see Cold hardiness)
  • Light and soil: in the wild, limestone rocks in semi-deciduous or mountain tropical forest, on shallow soils (rendzinas)
  • Habit and adult size: trunk 10 to 40 cm, lying down with age; 2 to 7 leaves, 0.7 to 1.9 m long
  • In the UK, US and Australia: Montgomery Botanical Center and Fairchild Tropical Botanic Garden (Florida), the Huntington (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 decumbens

It is recognised by its short trunk, which lies down over the rocks, by its leaves, four on average and drooping in old plants, and above all by its small, wine-red female cone. The original description (Vovides and colleagues, 2008) and the 2022 monograph give the following measurements:

  • Trunk: globose to cylindrical, partly or wholly buried, decumbent and branching, 9 to 20 cm according to the original description (10 to 40 cm according to the monograph), protected by reddish-brown leaf bases.
  • Leaves: 2 to 6 (4 on average), ascending and then hanging in older plants, reddish brown with whitish-grey hairs when they emerge, then dark green to olive green, 70 to 150 cm long (up to 190 cm according to the monograph); petiole unarmed or with a few short, scattered prickles.
  • Leaflets: 7 to 19 pairs (8 to 24 according to the monograph), leathery, flat, lanceolate to oblong, slightly sickle-shaped, 21 to 47 cm by 2.4 to 5 cm; articulation reddish brown.
  • Male cones: cylindrical, upright, 12 to 23 cm by 2.3 to 4.5 cm, green turning light brown.
  • Female cones: cylindrical to barrel-shaped, 9 to 11 cm by 7 to 8 cm, wine red with blackish-brown hairs when mature according to the monograph, whereas the original description calls them olive green turning dark green to brown, with metallic dark green scales; acute tip; 18 to 49 scales.
  • Seeds: oval, 1.2 to 2.6 cm, with white flesh turning beige to light brown.

Its chromosomes have been counted: 2n = 16.

Hybrids

No natural or garden hybrid has been documented.

Possible confusion

The closest species are those of central Veracruz:

  • Ceratozamia morettii has up to ten leaves, lying down to prostrate and coiled like a crook when they emerge, very prickly petioles, translucent leaflets and a green female cone with an apiculate tip; it grows in cloud forest on volcanic soils;
  • Ceratozamia mexicana has a green female cone with blackish-brown and grey hairs and an acuminate tip;
  • Ceratozamia huastecorum has upright leaves, oblanceolate leaflets and armed petioles;
  • Ceratozamia zoquorum and Ceratozamia becerrae, other dwarf species with broad leaflets, grow much further south and have oblong to oblanceolate leaflets.

The 2022 monograph also points out the reddish-brown young leaves with whitish-grey hairs, which separate it from Ceratozamia mexicana and Ceratozamia morettii. The name is shared with Zamia decumbens, a cycad of the Maya Mountains of Belize from another genus.

Taxonomy

Ceratozamia decumbens has never changed name. It is accepted by The World List of Cycads and by the WCVP, which records its publication in Novon 18, page 110.

It was described in 2008 by Andrew Vovides, Sergio Avendaño, Miguel Angel Pérez-Farrera and Jorge González-Astorga in the journal Novon. The authors first linked it to Ceratozamia latifolia, in a “latifolia complex” that also included Ceratozamia microstrobila, Ceratozamia huastecorum and Ceratozamia morettii. They compared the plant with the old and ambiguous descriptions of Miquel (1848), in particular Ceratozamia longifolia, before concluding that it was a new species.

Genetic studies later clarified its position. The phylogenomic study by Habib and colleagues (2023), based on 3,954 nuclear genes, places it as the sister group of all the other species of the Mexicana clade, one of the three main clades of the genus; it would have diverged from them towards the end of the Miocene, about 8 million years ago. In 2025, the integrative study by Medina-Villarreal and colleagues (Plant Species Biology) recognised it as one of the seven lineages of the Ceratozamia mexicana complex.

Etymology and history

The epithet comes from the Latin decumbens, “lying down with the tip rising”, and refers to the trunk of older plants, which lies on the ground (Haynes, 2022, as quoted by The World List of Cycads). The authors discovered the species during explorations in the mountains of central Veracruz in 1982, and plants have been grown since then at the Francisco Javier Clavijero botanic garden in Xalapa. Further collections were made in 1993 by Terrence Walters (Montgomery Botanical Center) and in 2002.

The type specimen was collected on 8 April 2005 by Sergio Avendaño and G. Alducin (number 5706), at Naranjal, near the Cueva de los Muñecos, at about 700 m; the holotype is kept in the XAL herbarium, with isotypes at HEM and MO. The authors deliberately left out precise localities to discourage illegal collecting.

Common names

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

In the wild

Ceratozamia decumbens is endemic to a small mountain range in central Veracruz. The monograph cites collections from the municipalities of Atoyac, Coetzala, Córdoba, Ixtaczoquitlán, Naranjal, Tequila, Tezonapa and Zongolica, between 445 and 1,100 m. It grows on karst limestone rocks in mountain tropical forest and cloud forest; at the type locality (712 m according to the original description), the forest is semi-deciduous tropical forest on shallow rendzinas, with Brosimum alicastrum, Bursera simaruba, Cedrela odorata and Chamaedorea palms in the understorey. The WCVP places it in the Mexican Gulf region.

The 2008 description gives this locality a semi-warm, subhumid climate: 1,000 to 1,200 mm (about 39 to 47 in) of rain a year, an annual mean of 21.5 °C (70.7 °F), extreme minimums of the coldest month of 12 to 13 °C (53.6 to 55.4 °F) and maximums above 34 °C (93.2 °F). The habitat belongs to the Pleistocene floristic refuge of Córdoba, at the foot of the Trans-Mexican Volcanic Belt.

Conservation status and regulation

Ceratozamia decumbens is assessed as Endangered (EN, criteria A2c; B1ab(i,ii,iii,v)) on the IUCN Red List, in the assessment by A.P. Vovides and J.D. Bösenberg 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).

Successive sources have proposed different categories:

  • in 2008, the describers recommended Critically Endangered (CR B2): three known populations, fewer than 1,000 individuals over less than 10 km², affected by the spread of coffee plantations, which removes the understorey;
  • in 2022, the monograph proposed Endangered, with populations of 100 to 150 adults plus juveniles and seedlings;
  • in 2025, the assessment of the cycads of Veracruz by Gómez Díaz gave it four localities, an extent of occurrence of 495 km² (about 190 square miles) and 63% of its habitat lost, and ranked it among the eight cycads of the state at highest risk of extinction.

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+ lists it by name; seeds are covered (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 decumbens

The Clavijero botanic garden in Xalapa has grown the species since 1982, and the plate of the original description was drawn from its plants. No growing guide has been published. Its habitat, limestone rocks under forest cover, points to a plant for partial shade in a very free-draining, limy substrate; this advice is deduced from the habitat.

Outdoor and in-ground cultivation

No outdoor planting has been documented outside Mexico. In frost-free subtropical gardens, a lightly shaded spot among limestone rocks would match its habitat; this is inferred, not tested.

Container cultivation

No container-growing report has been published. Small, with few leaves, it suits a pot under glass: free-draining, stony compost with some limestone, bright shade and a minimum winter temperature well above freezing, in line with the 12 to 13 °C (53.6 to 55.4 °F) minimums of its habitat.

In cultivation in the UK, US and Australia

In the United States, Montgomery Botanical Center (Coral Gables, Florida) lists one accession in its online catalogue and declares the species to BGCI PlantSearch, as do Fairchild Tropical Botanic Garden (Miami, Florida) and the Huntington (San Marino, California). The original description cites specimens collected by Terrence Walters in 1993 and kept at Fairchild’s herbarium (FTG). The only other holder declared to BGCI is the Clavijero botanic garden in Xalapa, Mexico. 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 seed; its branching trunk might provide offsets, but no source describes taking them. Seedlings bear two first leaves (eophylls).

Pests and diseases

No pest or disease has been documented for this species.

Cold hardiness

No cultivation report documents the cold tolerance of Ceratozamia decumbens; the only reference point is climatic. At the type locality, the extreme minimum of the coldest month stays between 12 and 13 °C (53.6 and 55.4 °F): the species is not exposed to frost in the wild, and nothing allows any cold tolerance to be attributed to it.

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 kept frost-free.

United Kingdom, United States and Australia

No cold record and no commercial hardiness rating have been published. The gardens that hold it in Florida and California do not state its growing conditions; 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; 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

Why “decumbens”?

Because the trunk of older plants lies on the ground or on the rocks, with its tip rising: that is the meaning of the Latin decumbens.

Where does it grow?

In a small mountain range of central Veracruz, near Córdoba, on limestone rocks in mountain tropical forest and cloud forest, between 450 and 1,100 m.

How can it be recognised?

By its small, decumbent trunk, its four or so leaves with broad, leathery leaflets, and its small, wine-red female cone with an acute tip.

Is it endangered?

Yes. It has been assessed as Endangered by the IUCN since 2022, and a 2025 study places it among the most threatened cycads of Veracruz, because of the spread of coffee plantations and crops.

Is it cold-hardy?

Probably not. At its type locality, the extreme minimum of the coldest month does not fall below 12 °C (53.6 °F), and no cold trial has been published.

Is it related to Ceratozamia mexicana?

Yes, but it is distinct. A 2025 study places it in the Ceratozamia mexicana complex as a separate lineage, and genetics place it at the base of the Mexicana clade.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Vovides, A.P., Avendaño, S., Pérez-Farrera, M.A. & González-Astorga, J. (2008). A new species of Ceratozamia (Cycadales, Zamiaceae) from Veracruz, Mexico. Novon 18(1): 109–114. https://doi.org/10.3417/2006063 [Original description: description, type, habitat, climate, chromosomes, recommended 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 [Description, range, altitudes, proposed status; 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 and dating; open access.]
  • 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, extent of occurrence, habitat loss; open access.]
  • Vovides, A.P. & Bösenberg, J.D. (2022). Ceratozamia decumbens. The IUCN Red List of Threatened Species 2022: e.T187826A1827950. https://doi.org/10.2305/IUCN.UK.2022-1.RLTS.T187826A1827950.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 [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.]