Zamia gentryi

Zamia gentryi is a cycad of north-western Ecuador, living in the premontane rainforests of Esmeraldas and Carchi provinces, near the Colombian border, between 300 and 1,800 m. This species of the genus Zamia, described in 1998 by Calaway H. Dodson, has a stem that lies on the ground or, more rarely, grows as an epiphyte, and leaves up to 2.5 m long with deeply grooved leaflets; it sometimes grows alongside Zamia roezlii. The IUCN rates it Endangered.

Key facts about Zamia gentryi

  • Accepted name: Zamia gentryi Dodson (1998), accepted by The World List of Cycads (version 2026.08.15) and by GBIF; POWO could not be consulted directly
  • Former names and synonyms: no synonym
  • Family: Zamiaceae, order Cycadales
  • Common names: no name attested, in English or in any other language
  • Natural range: Ecuador, Esmeraldas and Carchi provinces (Lita, Alto Tambo and the Awá reserve area); presence in neighbouring Colombia suggested by the author, not confirmed
  • IUCN status: Endangered (EN), criteria B1ab(iii)+2ab(iii), 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 data; a specialist nursery states that it will not stand frost (see Cold hardiness)
  • Light and soil: deeply shaded rainforest understorey (6,500 mm of rain a year at Alto Tambo), on a thin layer of soil over compact kaolin; in cultivation in full sun the stem becomes more upright and thicker
  • Habit and adult size: reclining stem up to 1 m long and 12 cm across (up to 70 cm tall and 25 cm across in cultivation); 5 to 9 leaves (13 in cultivation) up to 2.5 m long
  • In the UK, US and Australia: declared to BGCI only by San Diego Botanic Garden (California); grown by a San Diego nursery; 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 gentryi

The original description by Calaway H. Dodson, published in 1998 in the journal Novon, is precise. In the wild the stem reaches 1 m in length and 12 cm across but stays lying on the ground; in epiphytic plants it takes a characteristic U shape. In cultivation, in sun, it can partly straighten up, to 70 cm tall and 25 cm across.

Leaves and leaflets

The leaves, 5 to 9 on wild plants (up to 13 in cultivation), are stiff, upright to arching, and up to 2.5 m long. They emerge a bright reddish green and turn pale yellowish green on both sides. The petiole, 45 to 90 cm long, carries stout cylindrical prickles up to 1 cm long. The leaflets, opposite to subopposite, narrowly ovate, slightly oblique and slightly sickle-shaped, are up to 40 cm long and 3.5 to 6 cm wide, with an entire margin; their parallel veins are sunk into the blade on both sides and entirely hairless.

Jungle Music, a cycad nursery in San Diego, California, describes a medium-sized plant with a trunk “of several feet” and about 13 cm (5 in) across, upright, slightly arching leaves 1.8 to 2.4 m (6 to 8 ft) long, and leaflets 2.5 to 5 cm (1 to 2 in) wide and 15 to 20 cm (6 to 8 in) long whose prominent veins give the upper surface a corrugated, pleated look. The leaflet lengths it gives are much shorter than in the original description; the nursery does not say whether they come from young or cultivated plants.

Cones and seeds

  • Male cones: 1 to 7 per plant, on a reclining stalk up to 25 cm long, with an upright, wine-red fertile part 35 cm long and 3.8 cm across.
  • Female cone: single, reddish brown, barrel-shaped, up to 30 cm long and 15 cm across; its scales are covered in reddish-brown woolly hairs.
  • Seeds: obovoid, up to 3.5 cm long and 1.7 cm across, with a pink to reddish fleshy coat.

Hybrids

No hybrid is known. Dodson looked for signs of hybridisation where the species meets Zamia roezlii, between 300 and 400 m on the road from Lita to San Lorenzo, and found none.

Possible confusion

The main confusion is with Zamia roezlii, its closest relative according to Dodson, which lives from the Colombian coast to north-western Ecuador, from sea level to 300 m. The differences given in the original description are:

  • habit: a reclining stem (or U-shaped in epiphytes) in Zamia gentryi; a stiff, upright trunk up to 5 m in Zamia roezlii;
  • leaves: 5 to 13, against 15 to 45;
  • leaflets: pale yellowish green on both sides, with sunken, hairless veins, against dark green above, with raised veins that are hairy beneath, in Zamia roezlii;
  • male cones: wine-red, on a reclining stalk, against pinkish grey and upright;
  • female cones: up to 30 cm, with entirely woolly scales, against up to 90 cm in Zamia roezlii.

In young plants the distinction is harder. A French grower who saw both species in their habitat in 2012 reported on the Fous de palmiers forum that the difference lies mainly in the depth of the grooves on the leaflets, and that the male cones, white in Zamia roezlii and red in Zamia gentryi, are the surest clue. Jungle Music also notes the close relationship between the two species, Zamia roezlii forming a taller trunk.

Taxonomy

Zamia gentryi is an accepted name according to The World List of Cycads and GBIF; POWO could not be consulted directly. It was described in 1998 by Calaway H. Dodson, of the Missouri Botanical Garden, in Novon (8: 12–14). The type specimen, a male plant (C.H. Dodson and A.H. Gentry 17520A), was collected on 19 July 1988 at kilometre 18 of the road from Lita to San Lorenzo, near Alto Tambo (Esmeraldas), at 800 m; the holotype is kept at the national herbarium of Ecuador (QCNE), with isotypes at AAU, MO, NY, RPSC, SEL and U. The name has not changed since.

Place in the genus

Dodson considered the species close to Zamia roezlii. It is cited in a 2015 revision of Zamia montana and Zamia oligodonta by Calonje and colleagues, which compares the South American species with grooved leaflets. The transcriptome phylogeny of Lindstrom and colleagues (2024), which included a sample from Carchi, places it in the strongly supported West Andes clade (their clade VI), a group of mostly trunk-forming species of wet rainforest; the authors cite Zamia gentryi as the species that reaches the highest altitude recorded in the genus, in cloud forest, and Zamia roezlii, at the other extreme, as a plant of coastal swamps.

Etymology and history

The species honours Alwyn Howard Gentry (1945–1993), a botanist at the Missouri Botanical Garden and a great explorer of the Neotropical flora, who took part in collecting the type. Dodson, his friend, pays tribute to him in the description, published five years after his death. Plants were already grown at the Río Palenque Science Centre, in Ecuador, when the species was described.

Common names

No vernacular name is known, in English, Spanish or any other language.

In the wild

According to Dodson (1998), the species lives in extremely wet premontane rainforests of Carchi and Esmeraldas provinces, between 300 and 1,800 m; he thought it likely to occur in similar habitats of south-western Colombia, without having seen it there. At Alto Tambo, 6,500 mm of rain falls each year, and the soils are almost pure kaolin, very compact and impermeable: the plants do not sink into it but lie on the ground, their roots in the thin layer of soil that covers it. On the ground they grow in dense shade; some live as epiphytes.

Reproduction

Cones begin to appear in December, with the start of the heavy rains; male cones ripen in about 90 days, female cones become receptive at about the same time, and the seeds ripen in a year. Dodson noticed no scent and found no beetles on the male cones of plants grown at the Río Palenque Science Center, whereas at that site beetles commonly visit the powerfully fragrant cones of the Zamia lindenii plants that grow wild there (Dodson, 1998).

A field visit in 2012

In September 2012, a French grower visited a site near Lita with local guides and reported on the Fous de palmiers forum: in four hours he saw more than 40 plants, hard to spot in the dense, shaded forest except those whose new leaves were emerging copper-coloured; only two females carried cones; the leaves reached 2.5 m, with three per plant on average and six at most. He also reported forest burning in the area.

Conservation status and regulation

Zamia gentryi is rated Endangered (EN) on the IUCN Red List, in the assessment by Cristina López-Gallego published in 2022, under criteria B1ab(iii)+2ab(iii): a small range and area of occupancy, with a decline in habitat quality (The World List of Cycads; GBIF gives the same category; the Red List itself could not be consulted).

Like all Zamia except Zamia restrepoi, it falls under CITES Appendix II, where the genus has been listed since 4 February 1977. International trade in live plants requires an export permit. The listing carries annotation #4: seeds, pollen, seedlings and tissue cultures obtained in vitro and transported in sterile containers are not covered by CITES. In the European Union the species falls under Annex B of Regulation (EC) No 338/97, whose current list is set by Regulation (EU) 2026/1383, applicable since 29 June 2026.

Species+ has no separate entry for the species, which is covered by the listing “Zamia spp.” (checked on 3 October 2026). This general information does not replace the official texts: check the regulations in force before buying or exchanging plants or seeds, and ask the seller for proof of origin.

Growing Zamia gentryi

Zamia gentryi is a rare, warm-growing rainforest plant. It has been grown in Ecuador since at least the 1990s, notably at the Río Palenque Science Centre; Dodson notes that plants grown in full sun form partly upright stems up to 70 cm tall and 25 cm across, and up to 13 leaves, many more than in the wild. Jungle Music, which shows it among the container plants of its nursery, many of them mature and coning, calls it almost impossible to find for sale and describes it as a plant for filtered light that likes warmth, humidity and good air movement and will not tolerate temperatures below freezing. The French grower who saw it in the wild found it “more beautiful in shade than in sun”.

Simon Lavaud, of the French specialist nursery Cycadales.eu, places it in his group of the Zamia of Costa Rica, Panama and the lowland forests of South America, rated “difficult” outside the tropics (Lavaud, 2023). For this group he recommends:

  • a free-draining compost and water that are neutral to acid;
  • night temperatures around 22 °C (71.6 °F), with only brief spells at about 15 °C (59 °F) tolerated;
  • day temperatures of 28 to 30 °C (82.4 to 86 °F); most species tolerate 34 to 35 °C (93.2 to 95 °F), but heat peaks can damage new leaves;
  • high air humidity, between 70 and 90 per cent, for optimal growth;
  • in Europe, a glasshouse, conservatory, bright heated room or growth chamber.

These are recommendations for a group of species, not measurements made on Zamia gentryi. Its habitat, very wet, on compact soil where the roots stay near the surface, suggests a moist but airy compost; this is a deduction, not measured data. Note also that the species reaches 1,800 m in the wild, higher than most members of the group, but no minimum temperature has been recorded for its localities.

Outdoor and in-ground cultivation

Outdoor planting has only been documented in Ecuador, at Río Palenque, in a tropical climate. Elsewhere it is a plant for frost-free tropical gardens or for glasshouses.

Container cultivation

Jungle Music grows it in containers. Use a free-draining, airy compost that stays moist, bright filtered light or shade, high humidity and good air circulation, and allow for leaves up to 2 m or more in length: an adult needs a large glasshouse.

In cultivation in the UK, US and Australia

In short: very rare; the only garden record is in California.

  • United States: San Diego Botanic Garden (Encinitas, California) declares it to BGCI (queried on 25 October 2026); Montgomery Botanical Center lists no accession in its online catalogue. The Jungle Music nursery in San Diego shows it among its container-grown stock.
  • United Kingdom: no record in BGCI or in the online catalogues of British gardens (Edinburgh, Cambridge, Chelsea Physic Garden).
  • Australia: no record in BGCI or in the online catalogues of Australian gardens.

A BGCI declaration shows that a garden held the plant at some point, not that it is alive today, and it does not say whether the plant is grown outdoors or under glass.

Propagation

Like all Zamia, the species has separate male and female plants and is propagated from seed; young plants raised from seed were seen in the wild (2012) and in a glasshouse in France (2013). No germination data have been published. Seeds are exempt from CITES under annotation #4, but they must come from plants of legal origin.

Pests and diseases

No pest or disease has been documented for the species. For his group of lowland tropical Zamia, Lavaud (2023) warns that suboptimal conditions lead to weak growth and a risk of root rot.

Cold hardiness

No data exist on the cold tolerance of Zamia gentryi. Its range reaches 1,800 m, which makes it a plant of cool rainforest rather than hot lowlands, but no minimum temperature has been measured or reported for its localities. Jungle Music states that it will not tolerate temperatures below freezing.

Mediterranean and European experience

No in-ground planting has been reported in France or elsewhere in Europe, and no dated frost episode concerns the species. A French grower showed young Zamia gentryi raised in a glasshouse on the Fous de palmiers forum in May 2013, without temperature data. Lavaud (2023), who lives in Montpellier, notes that even in July and August, nights around 19 °C (66.2 °F) are below what the lowland Zamia of his group need, and that the air is far drier. For readers in Mediterranean-type climates, as in the UK, it is a glasshouse plant.

United Kingdom, United States and Australia

No dated cold record has been published. Trebrown, a British specialist nursery, gives the species a cold hardiness zone of 10a in its catalogue, without stating the basis of this commercial rating; it should not be taken as a measured limit. In the UK it needs a heated glasshouse.

Toxicity and precautions

No toxicity study specific to Zamia gentryi has been published. The risk is, however, documented in the genus and in other cycads: Zamia contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, and for Zamia furfuracea the ASPCA cites cycasin and BMAA, a neurotoxic amino acid, with vomiting, bloody diarrhoea and liver damage in dogs, cats and horses; the seeds are the most dangerous part. 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 traditional use has been documented.

Frequently asked questions

Where does Zamia gentryi grow?

In north-western Ecuador, in Esmeraldas and Carchi provinces, between 300 and 1,800 m, in very wet rainforest.

Is it an epiphyte?

Sometimes. Most plants grow on the ground, with a reclining stem, but some live on trees, where their stem takes a U shape.

How can it be told from Zamia roezlii?

By its reclining stem, fewer leaves, pale yellowish-green leaflets with sunken, hairless veins, and wine-red male cones. Zamia roezlii has an upright trunk up to 5 m and pinkish-grey male cones.

Why “gentryi”?

In honour of Alwyn H. Gentry (1945–1993), a botanist at the Missouri Botanical Garden who took part in collecting the type.

Is it endangered?

Yes. The IUCN has rated it Endangered since 2022, because of its small range and the decline of its habitat.

Can it be grown in the UK?

Only under glass, with warmth and humidity all year: it will not stand frost, and no cold tolerance data exist. It is also very hard to obtain.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Dodson, C.H. (1998). A new species of Zamia (Zamiaceae) from Ecuador. Novon 8(1): 12–14. [Protologue; full text consulted.]
  • Calonje, M., Morales, G., López-Gallego, C. & Roldán, F.J. (2015). A taxonomic revision of Zamia montana and Zamia oligodonta, with notes on their conservation status. Phytotaxa 192(4): 279–289. https://doi.org/10.11646/phytotaxa.192.4.5 [Cited by The World List of Cycads for the species; abstract consulted.]
  • 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 [Sample from Carchi; West Andes clade (clade VI); full text consulted.]
  • López-Gallego, C. (2022). Zamia gentryi. The IUCN Red List of Threatened Species 2022: e.T42153A69839536. [Current assessment (EN); cited by The World List of Cycads, Red List page not consulted.]
  • Lavaud, S. (2023). Comment cultiver les Zamia en climat tempéré. Cycadales.eu. [Growing advice for groups of species; read 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.]
  • 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.]