Ceratozamia fuscoviridis

Ceratozamia fuscoviridis is a cycad of east-central Mexico that grows in the cloud forests of the mountains of Hidalgo and the far north-west of Veracruz, between 1,300 and 1,900 m (about 4,300 to 6,200 ft). This species of the genus Ceratozamia owes its name to its leaflets, brown beneath and green above, and in many plants the young leaves emerge dark brown. First known from a single plant grown in Dublin, called “Ceratozamia fusca-viridis” in 1878, it was long treated as a mere form of Ceratozamia mexicana (Ceratozamia mexicana f. fuscoviridis) before being matched with wild populations in Hidalgo and recognised as a species in its own right. The IUCN Red List assesses it as Endangered.

Key facts about Ceratozamia fuscoviridis

  • Accepted name: Ceratozamia fuscoviridis W.Bull (1879), 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: Ceratozamia mexicana f. fuscoviridis (W.Bull) J.Schust. (1932); “Ceratozamia fusca-viridis” D.Moore (1878, a provisional and therefore invalid name); “Ceratozamia fuscoviridis D.Moore” (2006, an isonym with no nomenclatural standing)
  • Family: Zamiaceae, order Cycadales
  • Common names: no English name; in Mexico, teocintle, teosintle, teocentli, tepecintle or tepecintli, and xachitza or palma bendita in the Sierra Otomí-Tepehua
  • Natural range: Mexico, Hidalgo and north-western Veracruz (Huasteca karst), cloud forest between 1,300 and 1,900 m
  • IUCN status: Endangered (EN, criteria A2c; B1ab(i,ii,iii,iv,v)), assessment published in 2022; previously Critically Endangered
  • CITES and other protection: CITES Appendix I (whole genus, since 1985); Annex A in the European Union; “threatened” (A) under the Mexican standard NOM-059
  • Documented hardiness: no reliable data (see Cold hardiness)
  • Light and soil: in the wild, cloud forest; on basalt at Molango according to Osborne and colleagues (2006)
  • Habit and adult size: trunk upright then lying down, 20 to 90 cm; 10 to 70 ascending leaves, 0.9 to 2.15 m long (2022 monograph)
  • In the UK, US and Australia: Montgomery Botanical Center, Fairchild Tropical Botanic Garden and Naples Botanical Garden (Florida), the Huntington, Lotusland and UC Berkeley (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 fuscoviridis

It is a medium-sized cycad with upright leaves bearing many narrow, lanceolate, papery leaflets that curve downwards along their length. The young leaves emerge light green or dark brown depending on the plant, and brown-leaved plants keep a brownish underside. The female cone, brownish green with dark brown hairs when mature, is the best character. The 2022 monograph by Martínez-Domínguez and colleagues describes it as follows:

  • Trunk: above ground, upright then lying down, 20 to 90 cm long and 25 to 40 cm in diameter.
  • Leaves: 10 to 70, ascending, 92 to 215 cm long, light green or dark brown when they emerge, with whitish-grey hairs, hairless when mature; petiole 40 to 95 cm, dark green, armed with 14 to 60 (rarely 66) thin prickles about 1 to 3 mm long; rachis armed.
  • Leaflets: 28 to 67 pairs, opposite to nearly opposite, lanceolate, papery, sickle-shaped at the base and with a drawn-out tip; median leaflets 16.6 to 42 cm by 1.3 to 2.1 cm; veins green and light brown; articulation green and brown.
  • Male cones: cylindrical, upright, 22 to 30 cm by 5 to 8 cm, brownish yellow when they emerge, brownish green with reddish-brown hairs when mature.
  • Female cones: cylindrical, upright or hanging, 24 to 35 cm by 8.5 to 15 cm, green with brown hairs when they emerge, brownish green with dark brown hairs when mature, with a drawn-out tip; 49 to 195 scales.
  • Seeds: oval, 2 to 2.6 cm, with yellowish-white flesh turning light brown.

The same authors’ 2018 review gives slightly narrower figures for the cones (male cones 26.5 to 28 cm, female cones 8.5 to 10.5 cm in diameter, 99 to 143 scales). In both publications, the trunk measurements (20 to 90 cm by 25 to 40 cm) are exactly those given for Ceratozamia delucana; whether this is a coincidence or a copying error cannot be said, so these figures should be treated with caution.

The plant described in 1878 by David Moore, grown in Dublin, had a globular trunk, leaves 2.4 to 3 m long with 30 to 40 pairs of leaflets 20 to 25 cm by about 1.7 cm, dark brown beneath and dull green above, a petiole “beset with numerous short, sharp, strong prickles, more especially near the base”, and a female cone 15 to 20 cm long covered with brown hairs.

Hybrids

No natural hybrid has been documented. One garden hybrid is declared: the Huntington (San Marino, California) lists in BGCI PlantSearch a plant recorded as Ceratozamia fuscoviridis × Ceratozamia hildae; no description of it has been published.

Possible confusion

The main source of confusion is a close relative described in 2017 from populations long referred to Ceratozamia fuscoviridis. Several other species of the Sierra Madre Oriental look similar:

  • Ceratozamia chamberlainii, from southern San Luis Potosí to northern Hidalgo and Querétaro, has oblong, leathery leaflets with reddish-brown veins, a petiole with many short prickles and reddish-brown young leaves, and keeps that colour at the leaflet articulations of adult leaves; the discussion in the 2022 monograph calls the articulations of Ceratozamia fuscoviridis yellowish to greenish, whereas its description calls them green and brown;
  • Ceratozamia latifolia, from San Luis Potosí, has broader leaflets (up to 5 cm), an unarmed petiole and a half-buried trunk;
  • Ceratozamia sabatoi, from Hidalgo and Querétaro, has drooping leaves, linear leaflets and a bluish-green female cone;
  • Ceratozamia totonacorum, from the Sierra Norte de Puebla, also has brown young leaves, but the colour disappears in adult leaves, whereas it persists on the veins and underside in Ceratozamia fuscoviridis (Martínez-Domínguez and colleagues, 2018).

In the key of the 2018 review, Ceratozamia fuscoviridis is recognised by this combination: ascending leaves, lanceolate leaflets less than 2 cm wide with a flat blade, male cone scales without a curved-back tip, and a brownish-green female cone with dark brown hairs at maturity. Out of its habitat, a plant labelled “fuscoviridis” with no known origin may belong to a related species, especially Ceratozamia chamberlainii, whose populations carried this name before 2017: only the origin of the plant can settle the question.

Taxonomy

The name has an eventful history, traced by Osborne, Stevenson and Vovides (2006) and then by Calonje and Sennikov (2017). In March 1878, David Moore, director of the Glasnevin botanic garden near Dublin, presented to the Royal Dublin Society a coning female plant that he thought distinct from Ceratozamia longifolia and proposed to name, “provisionally”, Ceratozamia fusca-viridis. A name proposed provisionally is not valid under the botanical code. The following year, the London nurseryman William Bull took up the name with a brief description in his sales catalogue no. 154 (1879): that long-overlooked publication makes the name valid, which is why the author of the species is now Bull rather than Moore.

The name was then sunk into synonymy. In 1884, William Thiselton-Dyer, at Kew, placed it under Ceratozamia mexicana var. longifolia, noting that the plant seemed to be no more than a form with dark brown undersides to the leaflets. In 1932, Julius Schuster reduced it to a form of Ceratozamia mexicana. For more than a century, with no known wild locality and no herbarium specimen located, the name remained in the shadows (Osborne and colleagues, 2006).

It was restored to species rank by Roy Osborne, Dennis Stevenson and Andrew Vovides, in an article in Delpinoa entitled “What is Ceratozamia fuscoviridis?” (volume 48, dated 2006 and printed in December 2008). They found at Kew the Glasnevin specimen, a leaf cut onto three large sheets with a photograph of the cone, and matched the species with a wild population in Hidalgo known informally as “Ceratozamia Molango”. Unaware of Bull’s publication, they “validated” the name under Moore’s authority: Calonje and Sennikov (2017) showed that this name is an isonym with no nomenclatural standing, and designated the same Kew specimen as the neotype. Species+ still uses the old citation “Moore ex R.Osborne, D.W.Stev. & Vovides”.

The limits of the species were then refined. In 2017, Martínez-Domínguez, Nicolalde-Morejón and Stevenson separated the populations of southern San Luis Potosí and northern Hidalgo as Ceratozamia chamberlainii. In 2018, their review of the Ceratozamia of the Sierra Madre Oriental designated an epitype, a supporting specimen that fixes the interpretation of the neotype, collected at Molango (Hidalgo) on 31 March 2015. The 2022 monograph accepts the species and includes the Veracruz populations. The WCVP also accepts it, citing Bull’s catalogue (no. 154, page 4, 1879), and places it in the Mexican Gulf and north-eastern Mexico regions.

Genetically, the phylotranscriptomic study by Habib and colleagues (2023), which sampled it, places it in the latifolia subclade of the Mexicana clade, alongside Ceratozamia mexicana, Ceratozamia tenuis, Ceratozamia delucana, Ceratozamia morettii and Ceratozamia totonacorum. In practice, the name Ceratozamia mexicana f. fuscoviridis, still found on old labels, corresponds to the species Ceratozamia fuscoviridis, provided the plant really comes from this lineage.

Etymology and history

The epithet combines the Latin fuscus, “dark brown”, and viridis, “green”. According to Haynes (2022), as quoted by The World List of Cycads, it refers to the brownish underside and green upper side of the mature leaflets, which matches Moore’s description. Osborne and colleagues (2006) and the 2018 and 2022 monographs explain it instead by the dark brown or reddish-brown colour of the young leaves. The two readings partly overlap, but the sources do not say the same thing.

The story of the species begins under glass. According to Moore (1878), the Glasnevin plant had been brought directly from Havana and was said to be a native of Cuba, but he thought it more likely to have come from Mexico. It had been in the garden for about thirty years, had coned only once before, and was, to his knowledge, the only plant of its kind in British collections. A specimen of this plant reached Kew, recorded in 1881; it became the neotype (a leaf on three sheets and a female cone kept in spirit, according to The World List of Cycads).

According to Osborne and colleagues (2006), the parent plant was divided several times and all the Glasnevin plants descend from it; another plant was bought from William Bull & Sons in 1903. The same authors believe that Moore sent plants to the collector G. Garbari of Trento, whose collection was given in 1907 to the botanic garden of the University of Florence and included seven plants of Ceratozamia mexicana f. fuscoviridis, still alive in 2008. They also mention, without being able to prove it, an introduction by Thomas Coulter, physician to a mining company in Hidalgo from 1824 to 1829, who sent living plants to Dublin. A female cone formed again on the Glasnevin plant in 2007.

To link this plant with a wild population, Osborne and colleagues compared the measurements of Moore and of the type with those of “Ceratozamia Molango”, about 250 adult plants in two localities in the municipality of Molango (Hidalgo): median leaflets 16.5 to 36 cm by 1.4 to 2.2 cm, an often well-armed petiole, a large cylindrical female cone, and a population within reach of nineteenth-century collectors. The wild herbarium collections cited by the 2022 monograph all date from 1972 onwards.

Common names

There is no English name; the names on record are Mexican. Pulido and colleagues (2015) give “teosintle” as its Nahuatl name. According to Bonta and colleagues (2019), the Nahua people of the Huasteca of Hidalgo call it “teocintle”, “sacred” or “ancestral corn cob”, a name they also give to Zamia loddigesii; the same study records “teocentli” or “tepecintle” at Huayacocotla (Veracruz) and “xachitza” or “palma bendita” (“blessed palm”) in the Sierra Otomí-Tepehua (Hidalgo). The 2022 monograph records “teocintle”, “teocintli” and “tepecintli” in Veracruz. Beware: “teosinte” also refers to the wild relatives of maize, grasses of the genus Zea.

In the wild

Ceratozamia fuscoviridis is endemic to the central and southern Huasteca karst (Carso Huasteco), a limestone region of the Sierra Madre Oriental, from the mountains of central Hidalgo to north-western Veracruz. The herbarium collections cited by the 2022 monograph come from the municipalities of Eloxochitlán, Metztitlán, Molango de Escamilla, Tenango de Doria, Tlanchinol and Zacualtipán de Ángeles (Hidalgo) and Huayacocotla (Veracruz). It grows in cloud forest, between 1,300 and 1,900 m according to the 2022 monograph (1,800 to 1,900 m according to the 2018 review); at Molango, Osborne and colleagues (2006) found it only on basalt.

Long known from a single population, the species turned out to be more widespread. Pulido and colleagues (2015) recorded 29 scattered populations and studied six of them: in plots of 400 m², they counted 143 to 378 individuals, that is 0.36 to 0.95 plants per square metre. Seedlings were plentiful everywhere, a sign of good reproduction even in small forest fragments. A 2025 study of five populations showed that the plants grow in clusters, and recorded, for the first time in a Mexican cycad, signs of inhibition between size classes that suggest competition between individuals of the species (Pulido Silva and colleagues, 2025). The plants are dioecious; no pollinator specific to the species has been published.

Conservation status and regulation

Ceratozamia fuscoviridis is assessed as Endangered (EN, criteria A2c; B1ab(i,ii,iii,iv,v)) on the IUCN Red List, in the assessment by L. Martínez-Domínguez and F. Nicolalde-Morejón dated 13 August 2021 and 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 species was previously listed as Critically Endangered; Pulido and colleagues (2015), then the 2022 monograph, had proposed downgrading it to Endangered after new populations were found. Some sources still online give the old status. An older assessment, by J.S. Donaldson (2003), is also on record.

The threats are the clearing of cloud forests and changes in land use. The 2022 monograph records it in Los Mármoles National Park (Hidalgo). The 2025 assessment of the cycads of Veracruz by Gómez Díaz gives it 12 localities and an extent of occurrence of 4,375 km² (about 1,690 square miles), 36% of it in Veracruz, with 53% of the habitat lost and 99% of the range outside protected areas. In Mexico, the species is listed in the standard NOM-059-SEMARNAT-2010 as “threatened” (A), according to the same study.

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). International commercial trade in wild-collected plants is prohibited; plants propagated in cultivation may be traded with the required documents. 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 fuscoviridis

No growing guide has been published for Ceratozamia fuscoviridis, yet it has been in cultivation in Europe since the mid-nineteenth century: at Glasnevin, under glass, from about the 1840s (some thirty years before 1878, according to Moore), and in Florence, where the plants of the Garbari collection have been in the botanic garden since 1907 (Osborne and colleagues, 2006). These examples show great longevity in cultivation under cover, but no cultivation details have been published.

Its habitat, a humid and shaded mid-mountain cloud forest, suggests a plant for partial shade, in a free-draining, humus-rich substrate kept evenly moist; this advice is deduced from the habitat, not from growing trials. Its brown young leaves are its main ornamental appeal, but brown and green plants grow side by side in every population, and no source says whether the colour comes true from seed.

Outdoor and in-ground cultivation

Ganna Walska Lotusland, in Montecito (California), names Ceratozamia fuscoviridis among the notable species of its cycad garden, which is planted outdoors; the garden publishes no growing details for it. No other outdoor planting is documented. In mild, frost-free or nearly frost-free climates, a sheltered, lightly shaded spot in well-drained soil rich in organic matter would match its cloud-forest habitat; this is inferred, not tested.

Container cultivation

The Glasnevin and Florence plants show that it lives for a very long time in a pot or tub under glass; in Florence, according to the University of Florence’s Natural History Museum, most of the cycad collection is grown in pots in a cool glasshouse. Cones can be rare in such conditions: the Glasnevin female had coned only twice in about thirty years (Moore, 1878).

In cultivation in the UK, US and Australia

In the United States, Montgomery Botanical Center (Coral Gables, Florida) lists three accessions in its online catalogue and declares the species to BGCI PlantSearch, as do Naples Botanical Garden (Florida), the Huntington (San Marino, California) and the University of California Botanical Garden at Berkeley. Fairchild Tropical Botanic Garden (Florida) lists it in its online Garden Explorer (updated 16 October 2026), and Lotusland (Montecito, California) among the notable plants of its cycad garden. In Europe, BGCI lists the botanic gardens of Lyon (France), Zurich and Geneva (Switzerland). No garden in the United Kingdom 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; and given the old confusion with Ceratozamia chamberlainii, plants acquired before 2017 should be checked against their origin.

Propagation

No horticultural data specific to the species. Like all Ceratozamia, it is dioecious and is propagated from fertilised seed; in the wild, seedlings are abundant (Pulido and colleagues, 2015). The trunks sometimes branch into secondary trunks, and the Glasnevin plant was divided several times, which shows that offsets can be taken.

Pests and diseases

No pest or disease has been documented for this species.

Cold hardiness

No reliable data exist on its cold tolerance. Its sites reach 1,900 m in cloud forest, but no minimum temperature has been published for them.

Mediterranean and European experience

No outdoor cultivation has been reported in France or Italy, and the Jardin zoologique tropical in La Londe-les-Maures (Var, on the French Riviera) has published no observation of it. A grower in Ravenna (Emilia-Romagna, Italy) wrote on the Tropicamente forum in September 2012 that he had read that the species should be among the most cold-tolerant in the genus, but had not tested it in hard frost; in February 2012, when it was −8 °C (17.6 °F) outside, his greenhouse fell to −2 °C (28.4 °F). In June 2012, a grower in Ravenna also mentioned on the same forum a plant labelled “fuscoviridis”, kept frost-free in winter. This is not a hardiness measurement, and the identity of plants acquired before Ceratozamia chamberlainii was split off in 2017 is uncertain.

United Kingdom, United States and Australia

No cold record and no commercial hardiness rating have been published. Lotusland grows it outdoors in coastal southern California, without giving temperatures. In the UK it is a plant for a cool or heated glasshouse, as it has been in Ireland at Glasnevin since the nineteenth century.

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 pets, 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

Its leaves are mainly decorative and ritual. The 2022 monograph reports that they are used to make arches at the entrance of Catholic churches and to decorate walls during national holidays. Bonta and colleagues (2019) give photographed examples: a crown of leaves and a cone on the wall of a colonial church at Huayacocotla (Veracruz, 2009), an arch for the feast of a village in Hidalgo, and decorations in the church of San Juan Huazalingo (Hidalgo, 2016) for Michaelmas, which coincides with the feast of the maize deity Chicomexochitl. In the Sierra Otomí-Tepehua, a leaf blessed on Palm Sunday is tucked under the roof to protect the house from storms.

For the Nahua of the Huasteca of Hidalgo, Ceratozamia fuscoviridis and Zamia loddigesii are ancestors of maize. A story recorded at San Juan Huazalingo tells that before the arrival of the Spanish, maize grains were found in a teocintle, sown, and so maize was born (Bonta and colleagues, 2019). The same story says that teocintle was eaten at that time; no present-day consumption is documented.

Frequently asked questions

Why are the young leaves brown?

Not always: depending on the plant, they emerge light green or dark brown, in every population. A 1992 study of the “forma fuscoviridis”, with dark reddish-brown young leaves, described chloroplasts that are still immature in very young leaves and develop gradually. Brown plants keep a brownish underside when adult.

Is it a form of Ceratozamia mexicana?

No, not any more. It was filed under Ceratozamia mexicana from 1884 until the article by Osborne, Stevenson and Vovides (dated 2006, printed in 2008), which recognised it as a distinct species. The World List of Cycads, the 2022 monograph and the WCVP accept it; genetic analysis places it in the same subclade as Ceratozamia mexicana, as a separate species.

Why is the author Bull and not Moore?

Because Moore proposed the name only provisionally, in 1878, which makes it invalid. William Bull took it up in 1879 with a brief description in his sales catalogue: that publication is the one that counts, according to Calonje and Sennikov (2017).

How does it differ from Ceratozamia chamberlainii?

By its leaflets and petiole. Ceratozamia fuscoviridis has lanceolate, papery leaflets and a petiole with long, thin prickles; Ceratozamia chamberlainii has oblong, leathery leaflets with reddish-brown veins, many short prickles, and keeps reddish brown at the leaflet articulations.

Is it Critically Endangered or Endangered?

Endangered. The former Critically Endangered status was replaced by the assessment published in 2022, after new populations were found in Hidalgo and Veracruz. The species remains threatened by the loss of cloud forests.

Is it cold-hardy?

Nobody knows. No trial has been published; the only report, from Italy, concerns plants kept in a cold greenhouse that fell to −2 °C (28.4 °F) in February 2012, and the grower says he had not tested them in hard frost.

What does “teocintle” mean?

“Sacred” or “ancestral corn cob” in Nahuatl, according to Bonta and colleagues (2019). The Nahua of Hidalgo regard this cycad as an ancestor of maize. The word should not be confused with “teosinte”, the name of the wild grasses related to maize.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Moore, D. (1878). On a supposed new species of Ceratozamia. Scientific Proceedings of the Royal Dublin Society, n.s., 2: 112–114. [Publication of the provisional name “Ceratozamia fusca-viridis”; digitised text on Internet Archive.]
  • Bull, W. (1879). A retail list of new, beautiful & rare plants, no. 154: 4. London, King’s Road, Chelsea. [Valid publication of the name, according to The World List of Cycads and Calonje and Sennikov (2017).]
  • Osborne, R., Stevenson, D.W. & Vovides, A.P. (2006). What is Ceratozamia fuscoviridis? Delpinoa 48: 5–10 (volume dated 2006, printed in December 2008). [History of the Glasnevin plant and link with the Molango population.]
  • Calonje, M. & Sennikov, A.N. (2017). In the process of saving plant names from oblivion: the revised nomenclature of Ceratozamia fuscoviridis (Zamiaceae). Taxon 66(1): 158–164. https://doi.org/10.12705/661.9 [Abstract; neotype from The World List of Cycads.]
  • Martínez-Domínguez, L., Nicolalde-Morejón, F., Vergara-Silva, F. & Stevenson, D.W. (2018). Taxonomic review of Ceratozamia (Zamiaceae) in the Sierra Madre Oriental, Mexico. PhytoKeys 100: 91–124. https://doi.org/10.3897/phytokeys.100.23152 [Open access.]
  • 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 [Open access.]
  • Pulido, M.T., Vargas-Zenteno, M., Vite, A. & Vovides, A.P. (2015). Range extension of the endangered Mexican cycad Ceratozamia fuscoviridis Moore (teosintle): implications for conservation. Tropical Conservation Science 8(3): 778–795. https://doi.org/10.1177/194008291500800314 [Abstract.]
  • Pulido Silva, M.T., Flores-Vázquez, J.C., Vargas-Zenteno, M., Vite Reyes, A. & Vovides, A.P. (2025). Spatial distribution pattern of the endangered endemic cycad Ceratozamia fuscoviridis (Zamiaceae) in central Mexico. Plant Species Biology 40(6): 572–583. https://doi.org/10.1111/1442-1984.70030 [Abstract.]
  • Bonta, M., Pulido-Silva, M.T., Diego-Vargas, T., Vite-Reyes, A., Vovides, A.P. & Cibrián-Jaramillo, A. (2019). Ethnobotany of Mexican and northern Central American cycads (Zamiaceae). Journal of Ethnobiology and Ethnomedicine 15: 4. https://doi.org/10.1186/s13002-018-0282-z [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 [Open access.]
  • 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 [Open access.]
  • Morassi Bonzi, L., Medeghini Bonatti, P., Marini, C., Baroni Fornasiero, R. & Paoletti, C. (1992). Ultrastructural studies on differentiating chloroplasts in the “forma fuscoviridis” of Ceratozamia mexicana Brongn. New Phytologist 120(3): 427–434. https://doi.org/10.1111/j.1469-8137.1992.tb01083.x [Abstract.]
  • Martínez-Domínguez, L. & Nicolalde-Morejón, F. (2022). Ceratozamia fuscoviridis. The IUCN Red List of Threatened Species 2022: e.T212754607A2959711. https://doi.org/10.2305/IUCN.UK.2022-1.RLTS.T212754607A2959711.en [Current assessment, Endangered; category given by The World List of Cycads and GBIF, assessment date from 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.]