Zamia standleyi

Zamia standleyi is a cycad with an underground stem from northern Honduras and eastern Guatemala, where it grows in the lowland valleys that open onto the Caribbean, from Izabal in Guatemala to Olancho in Honduras. Described in 1989 by Bart Schutzman from plants of the Lancetilla valley, near Tela, this species of the genus Zamia is the most widespread of the Honduran zamias. Like the others, it is known locally as “camotillo” and has a long-standing reputation in Honduras as a dangerous poison. The IUCN rates it Least Concern.

Key facts about Zamia standleyi

  • Accepted name: Zamia standleyi Schutzman (1989), accepted by The World List of Cycads (version 2026.08.15) and by GBIF; POWO could not be consulted directly
  • Former names and synonyms: none; before 1989 herbarium specimens were mostly filed as Zamia furfuracea, with notes referring them to Zamia loddigesii or Zamia pumila
  • Family: Zamiaceae, order Cycadales
  • Common names: no English name; “camotillo” in Honduran Spanish, a name shared by all the zamias of the country
  • Natural range: Guatemala (Izabal) and Honduras (Atlántida, Colón, Cortés, Olancho, Santa Bárbara, Yoro); the collections known in 1989 all came from between sea level and 100 m
  • IUCN status: Least Concern (LC), assessment published in 2022
  • CITES and other protection: CITES Appendix II (whole genus, since 1977; seeds exempt under annotation #4); Annex B in the European Union
  • Documented hardiness: no figures (see Cold hardiness)
  • Light and soil: in the wild, semi-dry woodland, secondary scrub, moist hillsides and cultivated fields according to the original description (evergreen tropical forest according to a 2011 review); in cultivation, a free-draining compost (group advice from Cycadales.eu)
  • Habit and adult size: stem entirely underground; one to three arching leaves 20 to 100 cm long; sickle-shaped leaflets 20 to 45 cm by 1.5 to 3.5 cm
  • In the UK, US and Australia: Royal Botanic Gardens, Kew (UK, according to BGCI); Montgomery Botanical Center and Fairchild Tropical Botanic Garden (Florida), with nine other American gardens declared to BGCI; Royal Botanic Garden Sydney (Australia)
  • Toxicity: reputed to be highly poisonous in Honduras, where it is said to have been used as a poison; treat it as dangerous (see Toxicity and precautions)

How to recognise Zamia standleyi

The leaflets are the giveaway: sickle-shaped, slightly folded along their length and edged with very spiny teeth, a combination that, with cones held differently according to sex, sets Zamia standleyi apart from every other Zamia according to its original description (Schutzman, 1989). It shares its underground stem and smooth, rather leathery, finely toothed leaflets with the two other subterranean-stemmed zamias of northern Honduras, Zamia sandovalii and Zamia oreillyi (Nicolalde-Morejón and colleagues, 2011; Rivera García, 2016). The measurements below come from the original description.

  • Stem and leaves: stem entirely underground. Usually one to three leaves, depending on the size and condition of the plant, arching, 20 to 100 cm long, covered in fine white down when they emerge. Petiole 10 to 55 cm long, more or less spiny, especially towards the base (spines up to 5 mm); on large leaves the base of the petiole is swollen and spineless.
  • Leaflets: opposite to subopposite, long-lanceolate, sickle-shaped or nearly so, 20 to 45 cm long and 1.5 to 3.5 cm wide, with a slightly rolled margin carrying spiny teeth 0.5 to 4 mm long; red or bright green when they expand, then green, leathery and hairless. They are the least leathery of their group of species (0.40 to 0.50 mm thick). Zamia standleyi is the only species of the genus whose leaflets show a slight fold parallel to their long axis; the fold is clearer on small leaves and is lost in pressed specimens. In plants with red new leaves, the point where each leaflet joins the rachis stays bronzy red.
  • Male cones: coffee-coloured, cylindrical, 7 to 8 cm long and 1.5 to 2 cm across, on a peduncle 2 to 4 cm long, leaning to lying on the ground; the microsporophylls usually carry 16 pollen sacs.
  • Female cones: coffee-coloured and finely downy, barrel-shaped cylinders with a drawn-out tip, 8.5 to 11.5 cm long and 4.3 to 8.5 cm across, on a peduncle 2.5 to 3.8 cm long, held almost upright.
  • Seeds: about 1.6 cm long and 1 cm wide, salmon pink turning bright scarlet when ripe. Chromosome number 2n = 16.

Hybrids

No hybrid involving Zamia standleyi, natural or artificial, has been published.

Possible confusion

In Honduras the risk of confusion is low once the leaves are seen. Four zamias are known from the country, all endemic according to Rivera García (2016), even though Zamia standleyi also reaches Izabal in Guatemala. According to Nicolalde-Morejón and colleagues (2011), the three species with an underground stem are easily told apart by their vegetative and reproductive characters:

  • Zamia sandovalii (río Cangrejal valley, Atlántida): large leaves of about 2 m, with up to 68 pairs of sickle-shaped leaflets 16 to 31 cm by 2 to 3 cm (Nelson Sutherland, 2005);
  • Zamia oreillyi (Atlántida): small leaves of about 78 cm, linear-lanceolate leaflets of about 16 cm by 1 cm, and a tiny male cone on a long peduncle (Nelson Sutherland, 2005);
  • Zamia onan-reyesii (Merendón mountains, Cortés): easy to separate, since it is a shrub with an above-ground stem up to 2 m tall (Rivera García, 2016).

In Guatemala other zamias grow in Izabal and Alta Verapaz, such as Zamia variegata, with yellow-spotted leaflets, and the tree-forming Zamia tuerckheimii.

Further afield, Schutzman (1989) compared the species with Zamia splendens (Chiapas), Zamia purpurea (Veracruz and Oaxaca) and Zamia cremnophila (Tabasco). Its cones are almost identical in size, colour and shape to those of Zamia splendens, but the female cones of Zamia splendens lean over early and end up hanging; Zamia purpurea has small, dark brown female cones and elliptic leaflets, and the cliff-dwelling Zamia cremnophila has hanging leaves. The number of pollen sacs per microsporophyll also helps: usually 16 in Zamia standleyi and Zamia cremnophila, four or eight in Zamia purpurea, 20 in Zamia splendens. Herbarium specimens of Zamia standleyi were mostly labelled Zamia furfuracea and annotated Zamia loddigesii or Zamia pumila, two species unknown in Honduras; Zamia loddigesii has neither the folded, sickle-shaped leaflets nor the cones held differently according to sex.

Taxonomy

Zamia standleyi is an accepted name with no synonyms, according to The World List of Cycads and GBIF; POWO could not be consulted directly. Bart Schutzman described it in 1989 in Systematic Botany (volume 14, pages 214 to 219), in a paper titled “A new species of Zamia from Honduras”.

The plant had long been overlooked. In his 1982 master’s thesis on Mesoamerican zamias, Schutzman had treated it provisionally as a “Honduran loddigesii group”, without having seen its cones. Dried specimens lose the key leaflet characters and rarely carry cones, which he saw as the reason it had not been recognised earlier. A visit in 1985 to a private cycad collection in Tampa, Florida, where several fertile male and female plants were growing, convinced him: the cones closely resembled those of Zamia splendens and were quite unlike those of Zamia loddigesii. He also showed that a Fairchild Tropical Garden plant from Olanchito (Honduras), whose chromosomes had been counted in 1980 under the wrong name of Zamia tuerckheimii (accession FTG 76-977), belonged to the new species (Schutzman, 1989).

The species was included in the taxonomic revision of the zamias of “Mega-Mexico” published in 2009 by Nicolalde-Morejón, Vovides and Stevenson, and in the DNA barcoding work published by the same group in 2011, from samples supplied by Montgomery Botanical Center (Nicolalde-Morejón and colleagues, 2011). In the transcriptome-based phylogeny of Lindstrom and colleagues (2024), which included a wild-collected plant from Atlántida, it belongs to subclade III-B, the group of species restricted to Honduras and neighbouring eastern Guatemala and western Belize; in the concatenated trees it forms a small, well-supported group with Zamia oreillyi, Zamia sandovalii and Zamia purpurea.

Etymology and history

The epithet standleyi honours Paul C. Standley (1884–1963), an American botanist at the Field Museum of Natural History in Chicago, known for his work on the flora of Mexico and Central America (Haynes, 2022, followed by The World List of Cycads); Schutzman dedicated the species to him for his “outstanding as well as prolific floristic work”. Standley also wrote extensively on the flora of Honduras (Rivera García, 2016). He knew the plant, which he referred to Zamia furfuracea: in his 1931 flora of the Lancetilla valley he recorded it as “occasional in brushy places”, and in 1937 he described the root as highly poisonous (Schutzman, 1989).

The type was collected in August 1984 by Bart Schutzman (number 449) in the Lancetilla valley, near Tela (Atlántida). The holotype is kept at the herbarium of the University of Florida (FLAS), with isotypes at the National School of Agriculture of Honduras (ENA) and at Fairchild Tropical Garden (FTG). The species had been collected long before it was named: at San Pedro Sula as early as 1887, at Puerto Sierra in 1903, around Tela between 1922 and 1928 (including a collection by Standley), at La Lima in 1929 and at Coyoles, in Yoro, in 1938. By 1989 it had been grown in the United States for several years, and Fairchild Tropical Garden kept several plants in its outdoor beds (Schutzman, 1989).

Common names

There is no English name. In Honduras all zamias are called “camotillos”, from camote, the sweet potato (Rivera García, 2016); Schutzman already gave “camotillo” as the vernacular name of this species in 1989, noting that it was well known for its potent toxicity. The name is therefore not specific to Zamia standleyi. An indigenous name quoted by some online encyclopaedias has no verifiable source.

In the wild

Zamia standleyi grows in Guatemala, in the department of Izabal, and in northern Honduras, in the departments of Atlántida, Colón, Cortés, Olancho, Santa Bárbara and Yoro (The World List of Cycads). It is the most widely distributed of the Honduran zamias, the others being known from one or two localities. According to its original description it lives in the river valleys of northern Honduras, from San Pedro Sula eastwards to the Caribbean coast, and has been reported as far east as the río Plátano. It has been collected in semi-dry woodland, disturbed secondary scrub (matorral), on moist hillsides and in cultivated fields, always between sea level and 100 m (Schutzman, 1989).

The sources differ on its habitat: Nicolalde-Morejón and colleagues (2011) list it among the species of evergreen tropical forest, whereas the original description, based on the collections then known, describes drier or more open places. Lindstrom and colleagues (2024) also list it among the species adapted to seasonally dry habitats, which may lose their leaves during periods of extreme drought (field observation by A. Lindstrom). In 1989 Schutzman withheld precise localities for fear of over-collection, and called for fieldwork to find out whether the species reached Guatemala, where The World List of Cycads now records it.

The area between Alta Verapaz and Izabal in Guatemala and Atlántida, Cortés and Santa Bárbara in Honduras is one of the two main centres of diversity of the zamias of Mega-Mexico: seven species grow there, under a hot, wet climate with a mean annual temperature of about 25 °C (77 °F) and 3,000 to 4,000 mm of rain a year (Nicolalde-Morejón and colleagues, 2011). The pollinators, phenology and population structure of Zamia standleyi have not been described.

Conservation status and regulation

Zamia standleyi is rated Least Concern (LC) on the IUCN Red List (assessment by J.D. Bösenberg published in 2022, according to The World List of Cycads; category confirmed by GBIF; the Red List page could not be consulted). An earlier assessment, by D.W. Stevenson, was published in 2010. The relatively favourable rating reflects its wide range compared with the other Honduran zamias; in 2016, however, the state of the Honduran populations was still poorly known, and these plants are sought after by collectors (Rivera García, 2016).

Like all Zamia except Zamia restrepoi, which is in Appendix I, Zamia standleyi 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+ lists the species by name under the genus listing (checked on 3 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 standleyi

No growing advice specific to Zamia standleyi has been published, but the plant has been in cultivation in Florida for more than forty years. Schutzman (1989) found it attractive, especially the individuals with red new leaves, which keep that colour for quite some time. Simon Lavaud, of the French specialist nursery Cycadales.eu, places it in his group of Zamia from Mexico, Guatemala, El Salvador and Honduras, rated of “medium” difficulty: species that mostly come from climates with a marked dry season and tolerate dry air and a fairly dry compost in winter. For this group he advises a free-draining compost, slightly calcareous or neutral, any kind of water, winters at 5 to 10 °C (41 to 50 °F) with daytime rises to 20 to 25 °C (68 to 77 °F), and summers at 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; he insists on at least four to six months a year of summer-type temperatures (Lavaud, 2023). These are recommendations for a group, not trials with Zamia standleyi.

Outdoor and in-ground cultivation

The only documented outdoor cultivation is in tropical Florida: in 1989 Fairchild Tropical Garden, in the Miami area, kept several plants in its outdoor beds (Schutzman, 1989), and Montgomery Botanical Center, in Coral Gables, grows its cycads in an open-air collection. Outside the tropics, a sheltered, frost-free spot in very free-draining soil, in light shade, would be the most consistent approach; it has not been validated by published trials.

Container cultivation

No container-growing report has been published. With an underground stem and only one to three leaves, rarely longer than a metre, the species is of a size that can be kept in a large pot, following the group advice above: warm and well watered in summer, kept on the dry side and frost-free in winter. This is a deduction, not a tested result.

In cultivation in the UK, US and Australia

In short: one of the better-represented Central American zamias in American collections, with a single British and a single Australian record.

  • United States: the online catalogue of Montgomery Botanical Center (Coral Gables, Florida) lists ten accession numbers, the most recent from 2003 (20031245); one of them, 76977, carries the same number as the Fairchild accession FTG 76-977 from Olanchito cited by Schutzman. Fairchild Tropical Botanic Garden (Miami) lists the species in its online Garden Explorer (checked on 19 October 2026). BGCI also records it at The Huntington (San Marino, California), Ganna Walska Lotusland (Santa Barbara, California), the San Diego Zoo (California), Naples Botanical Garden and Marie Selby Botanical Gardens (Florida), Phipps Conservatory and Botanical Gardens (Pittsburgh, Pennsylvania), and in Hawaii at the National Tropical Botanical Garden, Honolulu Botanical Gardens and the botanical garden of the University of Hawaii at Hilo (catalogue and BGCI queried on 25 October 2026).
  • Australia: Royal Botanic Garden Sydney, which declares it to BGCI and lists it in its online Garden Explorer (checked on 19 October 2026).
  • United Kingdom: Royal Botanic Gardens, Kew, which declares it to BGCI; the record does not say where the plant is grown.

A BGCI declaration shows that a garden held the plant at some point, not that it is alive there today. Elsewhere, BGCI records it in Europe (Conservatoire botanique Pierre Fabre in France, Madeira Botanical Garden in Portugal, Palmengarten in Frankfurt, Prague Botanical Garden) and in Asia (Fairy Lake Botanical Garden in Shenzhen, Singapore Botanic Gardens).

Propagation

No data specific to the species. Like all Zamia, it has separate male and female plants and is propagated from fresh seed, after pollination; in 1985 male and female plants were already coning together in a Florida collection (Schutzman, 1989). Seeds are exempt from CITES under annotation #4, but should come from cultivated plants of legal origin.

Pests and diseases

At Fairchild Tropical Garden the tender new leaves are often damaged by the caterpillars of the atala butterfly (Eumaeus atala florida), a problem that Schutzman (1989) saw as limited to cycads planted outdoors in tropical regions. No disease specific to the species has been documented. In cultivation, Zamia are mainly at risk from rot in cold, sodden compost, and from scale insects.

Cold hardiness

There are no figures for the cold tolerance of Zamia standleyi. It lives in the tropical lowlands of northern Honduras and Izabal, with no cold season; nothing suggests that it tolerates frost.

Mediterranean and European experience

No cultivation result has been published in France or Italy, in the ground or in pots, and no dated frost episode concerns this species. At the Jardin zoologique tropical in La Londe-les-Maures (Var, on the French Riviera), no observation of it has been published. For readers in Mediterranean-type climates such as California or southern Australia, it should be treated as a frost-free plant, under glass in winter.

United Kingdom, United States and Australia

No cold record has been published. The only climatic pointer is its outdoor cultivation at Fairchild Tropical Garden, in tropical southern Florida, since at least the 1980s. Trebrown, a British nursery, gives it USDA zone 9b: a commercial rating, not a measured result. In the UK it needs a heated glasshouse.

Toxicity and precautions

Zamia standleyi has a reputation as a very poisonous plant in northern Honduras. Schutzman (1989) quotes Paul Standley (1937), who referred it to Zamia furfuracea: its root is highly poisonous and has been used at times for criminal poisonings as well as for poisoning noxious animals; according to a popular belief, a root that has been out of the ground for two days kills its victim in two days, one dug a week before kills in a week, and so on. In Honduras the phrase “te voy a dar camotillo” (“I’m going to give you camotillo”) is used as a threat (Rivera García, 2016). These stories provide no toxicological data, but they agree with the known danger of cycads.

No toxicity study specific to Zamia standleyi 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. 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

The only use recorded is as a poison against people and noxious animals, reported by Standley (1937) and repeated by Schutzman (1989) and Rivera García (2016). No food or medicinal use is documented.

Frequently asked questions

Who was Standley?

Paul C. Standley (1884–1963), an American botanist at the Field Museum in Chicago and a specialist in the flora of Mexico and Central America, who worked extensively on the plants of Honduras.

How can I recognise Zamia standleyi?

Mainly by its leaflets. They are sickle-shaped, slightly folded along their length and edged with very spiny teeth, a fold unique in the genus according to the original description; the female cones are held almost upright and the male cones lean over or lie on the ground.

Where does it grow?

In northern Honduras and in Izabal, Guatemala, at low altitude. The collections known in 1989 came from sea level to 100 m, in woodland, scrub, on moist hillsides and even in cultivated fields.

Is it endangered?

No, according to the IUCN, which rates it Least Concern. It is the most widespread of the Honduran zamias, although its populations have been little studied and are of interest to collectors.

What is a “camotillo”?

It is the name given in Honduras to all the zamias of the country. It comes from camote, the sweet potato, and is associated with the plants’ reputation as poisons.

Is it really poisonous?

Yes, it must be treated as such. No analysis concerns the species, but it is reputed to have been used as a poison in Honduras, and all the cycads studied contain serious toxins.

Is it hardy?

Almost certainly not. There are no cold data, and it comes from the tropical lowlands; outside the tropics it belongs in a heated glasshouse or conservatory in winter.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Schutzman, B. (1989). A new species of Zamia from Honduras. Systematic Botany 14(2): 214–219. https://doi.org/10.2307/2418907 [Original description; full text read in the copy published by The Cycad Society.]
  • Rivera García, I.S. (2016). Los venenosos camotillos en Honduras: el género Zamia (Zamiaceae). Desde el Herbario CICY 8: 77–80. [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.]
  • Nicolalde-Morejón, F., Vovides, A.P. & Stevenson, D.W. (2009). Taxonomic revision of Zamia in Mega-Mexico. Brittonia 61(4): 301–335. https://doi.org/10.1007/s12228-009-9077-9 [Reference revision; not consulted, cited by The World List of Cycads and by the 2011 paper.]
  • Nelson Sutherland, C.H. (2005 [2006–2007]). Dos plantas nuevas del género Zamia (Zamiaceae, Gymnospermae) en Honduras. Ceiba 46(1–2): 55–58. [Description of Zamia sandovalii and Zamia oreillyi; full text read.]
  • 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.]
  • Haynes, J.L. (2007). Overview of the cycad flora of Honduras. In: Vovides, A.P., Stevenson, D.W. & Osborne, R. (eds), Proceedings of Cycad 2005. Memoirs of the New York Botanical Garden 97: 444–453. [Review of the cycads of Honduras; cited by The World List of Cycads; not consulted.]
  • Bösenberg, J.D. (2022). Zamia standleyi. The IUCN Red List of Threatened Species 2022: e.T42157A69838675. https://doi.org/10.2305/IUCN.UK.2022-1.RLTS.T42157A69838675.en [IUCN assessment; reference checked on Crossref, category confirmed by GBIF; the Red List page could not be consulted.]
  • Stevenson, D.W. (2010). Zamia standleyi. The IUCN Red List of Threatened Species 2010: e.T42157A10670216. https://doi.org/10.2305/IUCN.UK.2010-3.RLTS.T42157A10670216.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.]