Zamia soconuscensis

Zamia soconuscensis is a cycad with an above-ground trunk from southern Mexico, endemic to the Sierra del Soconusco in south-western Chiapas, where it grows in the understorey between evergreen tropical forest and cloud forest. Described in 1988, this species of the genus Zamia is recognised by its young leaves covered in white down, its long, narrow, untoothed leaflets and its seeds, whose flesh turns salmon pink when ripe. In the most recent phylogeny of the genus it forms one of the seven major clades on its own. The IUCN rates it Endangered (2022 assessment).

Key facts about Zamia soconuscensis

• Accepted name: Zamia soconuscensis Schutzman, Vovides & Dehgan (1988), accepted by The World List of Cycads (version 2026.08.15), by GBIF and by the World Checklist of Vascular Plants, on which POWO is based; POWO could not be consulted directly
• Former names and synonyms: no synonym; before its description, collections were named Zamia sp. or Zamia loddigesii
• Family: Zamiaceae, order Cycadales
• Common names: none attested, in English or Spanish
• Natural range: Mexico, Chiapas (Sierra del Soconusco, or Sierra Madre de Chiapas); 900 to 1,400 m according to herbarium collections (Nicolalde-Morejón and colleagues, 2014)
• IUCN status: Endangered (EN), criterion B1ab(iii,v), 2022 assessment
• CITES and other protection: CITES Appendix II (whole genus, since 1977; seeds exempt under annotation #4); Annex B in the European Union; “in danger of extinction” (P) under the Mexican standard NOM-059-SEMARNAT-2010
• Documented hardiness: no measurement; a specialist nursery puts its group among the Zamia that tolerate winters at 5 to 10 °C (41 to 50 °F) with warmer days (see Cold hardiness)
• Light and soil: in the wild, forest understorey on clay rich in organic matter; in cultivation, a free-draining, slightly calcareous or neutral compost (group advice from Cycadales.eu)
• Habit and adult size: plants 0.3 to 0.5 m tall in the original description, with an above-ground trunk 5 to 25 cm across, upright in young plants, then lying down; leaves 0.4 to 1.9 m long
• In the UK, US and Australia: Montgomery Botanical Center and Fairchild Tropical Botanic Garden (Florida), The Huntington, San Diego Botanic Garden, Naples Botanical Garden and the University of Hawaii at Hilo (US); no British or Australian record
• Toxicity: no data specific to the species; treat it as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Zamia soconuscensis

Young leaves covered in white down, long and narrow leaflets without teeth, and an above-ground trunk that comes to lie on the ground with age are its most visible features. The original description (Schutzman, Vovides and Dehgan, 1988) gives:

• Habit: separate male and female plants, looking like a small palm, 0.3 to 0.5 m tall.
• Trunk: thick and above ground, upright in young plants then lying down, rarely branched, 5 to 25 cm across; the leaf bases are massive and spineless; the cataphylls, narrowly triangular and downy, measure about 4.5 cm by 1.5 cm.
• Leaves: one to many depending on the size and condition of the plant, spreading, 0.4 to 1.9 m long and 0.25 to 0.64 m wide; they emerge covered in fine white down and become green, leathery and hairless.
• Leaflets: opposite to nearly opposite, long-lanceolate, sickle-shaped or almost so, 14 to 33 cm long and 0.6 to 1.4 cm wide, with an entire margin slightly rolled under and a sharp tip.
• Petiole and rachis: more or less prickly, especially towards the base of the petiole, with cylindrical prickles 0.5 to 4 mm long.
• Male cone: cylindrical to conical, dark brown, 9.5 cm by 2.1 cm, on a peduncle 5.5 cm long; each scale carries 16 to 24 pollen sacs.
• Female cone: cylindrical, barrel-shaped with a drawn-out tip, covered in fine dark brown down, 12 to 21 cm long and 7 to 10 cm wide, on a peduncle 3.4 cm long; two ovules per scale.
• Seeds: ovoid, regular or angular; the flesh (sarcotesta) is white before ripening and then salmon pink; the bare seed (sclerotesta), pale beige, measures 2.2 to 2.6 cm by 1.4 to 1.9 cm and carries six to eight faint longitudinal grooves.

The species has 2n = 16 chromosomes, with a fairly symmetrical karyotype (symmetry index 2.08). The authors noted that these large chromosomes tended to stick end to end and to break during preparation, a problem solved by a 12-hour cold treatment (Schutzman and colleagues, 1988).

Hybrids

No present-day hybrid of Zamia soconuscensis has been documented. The transcriptome-based phylogeny of Lindstrom and colleagues (2024) did, however, detect ancient reticulation, that is, hybridisation between lineages: according to their analysis, the ancestors of the Isthmus clade (Costa Rica and Panama) inherited from both the lineage of Zamia soconuscensis and the common ancestor of the South American clades.

Possible confusion

The authors of the description compared the species with Zamia inermis, from Veracruz, several hundred kilometres to the north-west. According to the Latin diagnosis, Zamia soconuscensis differs in its white, downy young leaves, its more sickle-shaped and less leathery leaflets, its prickly and barely hairy petiole (inermis means “unarmed”), its slender, reclining above-ground trunk, its brown cones and its large, angular, finely grooved seeds. The cones of Zamia inermis are yellowish brown or beige, those of Zamia soconuscensis coffee-coloured to dark brown when ripe (Schutzman and colleagues, 1988).

The authors also cited Zamia tuerckheimii, from Guatemala and Honduras, and Zamia monticola: all these species have trunks, large cones, sickle-shaped leaflets with few or no teeth and 2n = 16. Zamia soconuscensis has long, narrow, lanceolate, relatively thin leaflets without teeth, whereas Zamia tuerckheimii has broader, elliptic to oblanceolate leaflets, slightly toothed at the tip. Nicolalde-Morejón and colleagues (2011) add that Zamia tuerckheimii, Zamia soconuscensis and Zamia inermis share an aerial stem and leaflets with entire margins, but are not difficult to identify.

Another confusion is historical: in the Soconusco the species grows alongside Ceratozamia matudae (spelt “matudai” in the description), and sterile specimens of the two plants were similar enough to be mixed up in the herbarium (see Etymology and history). The two genera are easy to tell apart by their cones: the scales of Ceratozamia carry two horns.

Taxonomy

Zamia soconuscensis is accepted by The World List of Cycads, by GBIF and by the World Checklist of Vascular Plants of Kew; POWO could not be consulted directly. The species was described in 1988 by Bart Schutzman, Andrew P. Vovides and Bijan Dehgan in the Botanical Gazette (volume 149, issue 3), in an article that also described Zamia cremnophila (pages 347 to 360; Zamia soconuscensis on pages 347 to 351, figures 1 to 3). The type is a collection made by Eizi Matuda in February 1939 (Matuda 2659) in Chiapas: the holotype is kept at the Field Museum in Chicago (F), with isotypes at MICH and CR. The name has no synonym, either in The World List of Cycads or in Species+.

A lineage of its own

The authors considered it close to Zamia inermis. The phylogeny of Lindstrom and colleagues (2024), which divides the genus into seven major clades matching geographical regions and sampled a plant from Chiapas, shows an unexpected position: Zamia soconuscensis forms clade IV on its own and is closer to the species of southern Central America and South America than to the other Mexican and northern Central American Zamia, although these are geographically nearer. This placement had already been found by Calonje and colleagues (2019), cited by Lindstrom and colleagues; the split of this lineage, confined to Chiapas, is dated to about 22.5 million years ago. The authors describe it as a morphologically very distinct species.

Etymology and history

The epithet refers to the Sierra del Soconusco, also called the Sierra Madre de Chiapas, where the species is native (Schutzman and colleagues, 1988; Haynes, 2022, followed by The World List of Cycads).

During his thorough study of the Soconusco district, the botanist Eizi Matuda collected the plant as early as December 1937 without recognising it as new: he named it Zamia sp. or Zamia loddigesii. One of his sterile specimens, from an area where it grows alongside the Ceratozamia named after him, had been mixed with that species before being relabelled. Further collections by Matuda date from 1938 and 1939. The authors of the description found the plant again in January 1985, during the second of two expeditions to southern Chiapas; more specimens were collected in 1985 and 1986 (Schutzman and colleagues, 1988).

Common names

There is no English name, and no common name is attested in Spanish; Species+ gives none.

In the wild

According to The World List of Cycads, Zamia soconuscensis lives only in Mexico, in the state of Chiapas. The original description places it in the understorey of the transition zone between “selva alta perennifolia” (tall evergreen tropical forest) and “bosque mesófilo de montaña” (cloud forest), on clay rich in organic matter. Lindstrom and colleagues (2024) describe it growing in small, isolated pockets of cloud forest on steep mountain slopes, and illustrate it in montane forest in Chiapas.

The authors of 1988 considered it probably very localised, known only from small areas of the Sierra del Soconusco, and did not publish the exact localities, to protect it from commercial collecting; undocumented reports mentioned other localities in the same range. They also recalled that the Soconusco has been proposed as one of the five major refuges of Mexico (Toledo, 1982). The description gives no altitude; from herbarium collections, Nicolalde-Morejón and colleagues (2014) place the species between 900 and 1,400 m.

Conservation status and regulation

Zamia soconuscensis is rated Endangered (EN) on the IUCN Red List under criterion B1ab(iii,v), in an assessment by J.D. Bösenberg published in 2022 (The World List of Cycads; category confirmed by GBIF; the Red List page could not be consulted). This criterion refers to a small range, fragmented or limited to few locations, with a continuing decline in habitat quality and in the number of mature plants. An earlier assessment, by A. Vovides and J. Chemnick, was published in 2010.

As early as 1988 the authors reported that their study of the habitat had been cut short by the conversion of land to coffee plantations and maize fields, and that living plants were being collected to be rescued and grown in botanic gardens, at the biological station of INIREB (a research institute in Xalapa, Veracruz) and elsewhere. In Mexico the species is classed as “in danger of extinction” (P) under the NOM-059-SEMARNAT-2010 standard (Nicolalde-Morejón and colleagues, 2014).

Like all Zamia except Zamia restrepoi, which is in Appendix I, Zamia soconuscensis falls under CITES Appendix II, where the genus has been listed since 4 February 1977. The listing carries annotation #4 (version adopted at CoP20, in force on 5 March 2026): seeds, pollen, seedlings and tissue cultures obtained in vitro and transported in sterile containers, and cut flowers of artificially propagated plants, are not covered by CITES. International trade in the plants themselves, on the other hand, requires an export permit. In the European Union the species is listed in Annex B of Regulation (EC) No 338/97, whose annexes are now set by Regulation (EU) 2026/1383, applicable since 29 June 2026. Species+ names the species and confirms this status (checked on 13 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 Zamia soconuscensis

No botanic garden has published growing advice specific to the species. Simon Lavaud, of the French specialist nursery Cycadales.eu in Montpellier, places Zamia soconuscensis among the Zamia of Mexico, Guatemala, El Salvador and Honduras, which he rates of “medium” difficulty: most come from climates with a marked dry season and tolerate dry air and a fairly dry compost in winter (Lavaud, 2023). For this group he advises:

• a free-draining compost, slightly calcareous or neutral; any kind of water;
• in winter, 5 to 10 °C (41 to 50 °F) with daytime rises to 20 to 25 °C (68 to 77 °F); moderate tolerance of long cool spells without rises above 20 °C (68 °F), provided the compost stays fairly dry without drying out completely;
• in summer, 15 to 20 °C (59 to 68 °F) at night and 25 to 30 °C (77 to 86 °F) by day, with up to 40 °C (104 °F) tolerated if watering is generous;
• at least four to six months a year of summer-type temperatures: grown all year at “winter” temperatures, these tropical plants decline.

These are recommendations from experience for a group of species, not measurements made on Zamia soconuscensis. The same author places Zamia tuerckheimii and Zamia monticola, the relatives cited in the description, in the more demanding group of lowland forest species; no source explains the difference.

Outdoor and in-ground cultivation

No planting in the ground has been documented outside Mexico and the subtropical gardens that hold it (see below). Its habitat suggests a frost-free climate with warm, humid summers; this is a deduction, not a tested result.

Container cultivation

No container-growing report has been published. Following the nursery’s group advice, a pot that spends the summer outdoors or in a warm glasshouse and the winter in a bright, sheltered place at around 5 to 10 °C (41 to 50 °F), with a rather dry compost, would be the most consistent approach; this is a deduction from the group advice, not a published experience with the species.

In cultivation in the UK, US and Australia

In short: well represented in American botanic gardens, absent from British and Australian records.

• United States: the online catalogue of Montgomery Botanical Center (Coral Gables, Florida) lists nine accession numbers, 99471, 20011293, 20030717 to 20030721, 20150386 and 20160078, which by their numbering date from 1999 to 2016; Fairchild Tropical Botanic Garden (Miami) lists it in its online Garden Explorer (checked on 19 October 2026). BGCI also records it at The Huntington (San Marino, California), San Diego Botanic Garden (Encinitas, California), Naples Botanical Garden (Florida) and the botanical garden of the University of Hawaii at Hilo (catalogue and BGCI queried on 25 October 2026).
• Australia: no record in BGCI or in the online catalogues of Australian gardens.
• United Kingdom: no record in BGCI or in the online catalogues of British gardens.

A BGCI declaration shows that a garden held the plant at some point, not that it is alive there today. In Mexico, BGCI records it at the botanical garden of the Institute of Biology (UNAM) in Mexico City, the Francisco Javier Clavijero Botanic Garden in Xalapa, the Dr. Faustino Miranda Botanic Garden in Chiapas and the Culiacán Botanic Garden (Sinaloa).

Propagation

Like all Zamia, the species has separate male and female plants and is propagated from seed; a plant of each sex is needed to obtain seed in cultivation. No germination data specific to the species have been published; the original description illustrates a seedling. Seeds are exempt from CITES permits; make sure they come from cultivated plants.

Pests and diseases

No pest or disease specific to the species has been documented. Cycadales.eu points out that a very wet compost encourages rot in cold weather, and that species of the Mexican group have the advantage of tolerating a drier compost in winter (Lavaud, 2023). Cultivated Zamia can also host scale insects.

Cold hardiness

There is no measurement of the cold tolerance of Zamia soconuscensis, and no frost episode concerns the species. Cycadales.eu gives for its group a winter tolerance of 5 to 10 °C (41 to 50 °F) with warmer days (Lavaud, 2023): this is not a threshold measured on the species, and no source indicates that it tolerates frost.

Mediterranean and European experience

No in-ground cultivation result has been published in France or Italy. At the Jardin zoologique tropical in La Londe-les-Maures (Var, on the French Riviera), no observation of this species has been published. For readers in Mediterranean-type climates such as California or southern Australia, the nursery’s group advice points to a pot plant kept frost-free in winter.

United Kingdom, United States and Australia

No cold record has been published, on forums or by botanic gardens. The American collections that hold it are in southern Florida, Hawaii and southern California, where winters are mild. In the UK it would need a heated glasshouse in winter.

Toxicity and precautions

No toxicity study specific to Zamia soconuscensis has been published. The risk is, however, well documented in cycads: Zamia contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, harmful to the liver and nervous system, and cycads also contain a neurotoxic amino acid, BMAA; the seeds are the most dangerous part. Within the genus, the ASPCA lists Zamia furfuracea as toxic to dogs, cats and horses. In the absence of evidence to the contrary, treat the plant as poisonous: keep seeds and leaves out of reach of children and animals, and wear gloves to clean seeds. If any part is swallowed, contact a poison centre, a doctor or a vet straight away.

Traditional uses

No use specific to Zamia soconuscensis has been documented.

Frequently asked questions

Where does Zamia soconuscensis grow?

Only in Mexico, in the Sierra del Soconusco (Chiapas), in the understorey between evergreen tropical forest and cloud forest, on clay rich in organic matter, between 900 and 1,400 m according to herbarium collections.

How can I recognise it?

By its young leaves covered in white down, its long, narrow leaflets (14 to 33 cm by 0.6 to 1.4 cm) without teeth, its above-ground trunk that comes to lie on the ground, and its seeds with salmon-pink flesh when ripe.

Is it a palm?

No. Despite the small-palm look noted in its description, it is a cycad (Zamiaceae), a seed plant without flowers that reproduces through male and female cones borne on separate plants.

Why does it interest botanists?

Because it forms one of the seven major clades of the genus on its own, closer to the southern species than to its Mexican neighbours, and because an ancient hybridisation event links its lineage to that of the Zamia of Costa Rica and Panama (Lindstrom and colleagues, 2024).

Is it endangered?

Yes. The IUCN rates it Endangered (2022), because of its small range and the decline of its habitat, converted to coffee plantations and maize fields. It is listed in CITES Appendix II and classed as “in danger of extinction” under the Mexican standard.

Can I grow it in a temperate climate?

Probably, in a pot kept frost-free in winter, following a specialist nursery’s advice for its group; no cultivation report on the species itself has been published.

Is it poisonous?

It must be assumed so. No analysis concerns the species, but the cycads studied contain serious toxins, especially in the seeds.

Further reading on Succulentes

• How to Grow Cycads from Seed: Germination, Seedling Care and Propagation Setup
• Watering Cycads: Common Mistakes and How to Avoid Them
• Is Sago Palm Toxic to Dogs, Cats & Children? What to Know

Sources

Reference sites

• The World List of Cycads (version 2026.08.15), Zamia soconuscensis: https://cycadlist.org/scientific_name/553 — authors, publication, type (Matuda 2659, F; MICH, CR), range, IUCN status and criterion, etymology. Checklist of the IUCN Cycad Specialist Group, reliable; reread on 25 October 2026.
• The Cycad Society, original description of Zamia soconuscensis (Schutzman, Vovides and Dehgan, Botanical Gazette 149(3): 347–360, 1988): https://www.cycad.org/documents/descriptions/Zamia/Zamia-soconuscensis.pdf — description, history of the discovery, habitat, karyotype, comparison with Zamia inermis and Zamia tuerckheimii. Copy of the original description distributed by a specialist society; the PDF is truncated, its page images were read by optical character recognition (October 2026).
• World Checklist of Vascular Plants (WCVP, Royal Botanic Gardens, Kew), Zamia soconuscensis Schutzman, Vovides & Dehgan, via GBIF: https://www.gbif.org/species/207874736 — accepted name, place of publication “Bot. Gaz. 149: 347 (1988)”. Kew reference list underlying POWO; dataset of 4 June 2026, queried through the GBIF API on 25 October 2026.
• Revista Mexicana de Biodiversidad, Biodiversidad de Zamiaceae en México (2014): https://doi.org/10.7550/rmb.38114 — state, altitude (900 to 1,400 m), NOM-059-SEMARNAT-2010 category. Peer-reviewed article; full text read.
• Revista Mexicana de Biodiversidad, Perspectivas sistemáticas de Zamia (Zamiaceae) en Megaméxico (2011): https://www.redalyc.org/pdf/425/42521043001.pdf — group of Zamia tuerckheimii, Zamia soconuscensis and Zamia inermis (aerial stem, entire leaflets). Open-access peer-reviewed article; full text read.
• PubMed Central, Lindstrom et al. (2024), Annals of Botany: https://pmc.ncbi.nlm.nih.gov/articles/PMC11560380/ — single-species clade IV, unexpected placement, habitat (cloud forest on steep slopes), ancient reticulation, divergence date. Peer-reviewed article; full text read.
• Species+ (UNEP-WCMC), Zamia soconuscensis: https://speciesplus.net/species#/taxon_concepts/25664/legal — CITES Appendix II (genus listed since 4 February 1977, annotation #4), EU Annex B; no common name or synonym. Official CITES and EU database; queried on 13 October 2026.
• Commission Regulation (EU) 2026/1383: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=OJ:L_202601383 — annexes to Regulation (EC) No 338/97 in force since 29 June 2026. Official text.
• Montgomery Botanical Center, online catalogue of living collections (BG-BASE): https://websites.rbge.org.uk/cgi-bin/nph-readbtree.pl/dataset=CYCADS/filename=n132_cyc/firstval=1?ETI=zamia%20soconuscensis* — nine accession numbers (1999 to 2016). Catalogue kept by the garden; queried on 25 October 2026.
• BGCI PlantSearch, Zamia soconuscensis: https://plantsearch.bgci.org/ — ten declaring gardens, six in the United States and four in Mexico. Global database of botanic garden collections; a declaration does not prove that the plant is still alive; queried through its API on 25 October 2026.
• GBIF, Zamia soconuscensis: https://www.gbif.org/species/5284079 — accepted name and current IUCN Red List category (EN). Reference data infrastructure; queried through its API on 25 October 2026.
• Cycadales.eu (Simon Lavaud), Comment cultiver les Zamia en climat tempéré (6 January 2023, updated 27 May 2023, in French): https://cycadales.eu/comment-cultiver-les-zamia-en-climat-tempere/ — group of the Zamia of Mexico, Guatemala, El Salvador and Honduras, conditions advised for the group. Specialist nursery: advice from experience for a group of species; reread on 25 October 2026.
• ASPCA Animal Poison Control, Cardboard Cycad: https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/cardboard-cycad — toxicity of Zamia furfuracea to dogs, cats and horses. Veterinary poison centre, reliable; genus-level data.

Bibliography

• Schutzman, B., Vovides, A.P. & Dehgan, B. (1988). Two new species of Zamia (Zamiaceae, Cycadales) from southern Mexico. Botanical Gazette 149(3): 347–360. [Original description of Zamia soconuscensis (pp. 347–351) and of Zamia cremnophila; read in the copy distributed by The Cycad Society.]
• Lindstrom, A., Habib, S., Dong, S., Gong, Y., Liu, J., Calonje, M., Stevenson, D. & Zhang, S. (2024). Transcriptome sequencing data provide a solid base to understand the phylogenetic relationships, biogeography and reticulated evolution of the genus Zamia L. (Cycadales: Zamiaceae). Annals of Botany 134(5): 747–768. https://doi.org/10.1093/aob/mcae065 [Full text read on PubMed Central.]
• Nicolalde-Morejón, F., González-Astorga, J., Vergara-Silva, F., Stevenson, D.W., Rojas-Soto, O. & Medina-Villarreal, A. (2014). Biodiversidad de Zamiaceae en México. Revista Mexicana de Biodiversidad, suppl. 85: S114–S125. https://doi.org/10.7550/rmb.38114 [Full text read.]
• Nicolalde-Morejón, F., González-Astorga, J., Vergara-Silva, F. & Vovides, A.P. (2011). Perspectivas sistemáticas de Zamia (Zamiaceae) en Megaméxico: de la taxonomía alfa a los códigos de barras genéticos. Revista Mexicana de Biodiversidad 82(2): 341–355. [Full text read.]
• Bösenberg, J.D. (2022). Zamia soconuscensis. The IUCN Red List of Threatened Species 2022: e.T42156A69838890. https://doi.org/10.2305/IUCN.UK.2022-1.RLTS.T42156A69838890.en [Current assessment (EN B1ab(iii,v)); reference checked on Crossref, category confirmed by GBIF; the Red List page could not be consulted.]
• Vovides, A. & Chemnick, J. (2010). Zamia soconuscensis. The IUCN Red List of Threatened Species 2010: e.T42156A10669906. https://doi.org/10.2305/IUCN.UK.2010-3.RLTS.T42156A10669906.en [Earlier assessment; reference checked on Crossref; category not verified.]
• Lavaud, S. (2023). Comment cultiver les Zamia en climat tempéré. Cycadales.eu. [Growing advice for groups of species; read directly.]
• 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; not consulted directly.]
• 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; consulted directly.]