Zamia imbricata

Zamia imbricata is a small cycad from Colombia, known from a single locality in the middle Magdalena valley, in the municipality of La Dorada (Caldas department), where it grows on steep slopes in tropical moist forest between 200 and 245 m above sea level. Described in 2021, this species of the genus Zamia is recognised by its flat, almost horizontal leaves, whose small leaflets overlap like the tiles of a roof, hence its name. Its authors found only fifteen plants and recommend that it be listed as Critically Endangered; the IUCN has not yet assessed it.

Key facts about Zamia imbricata

  • Accepted name: Zamia imbricata Calonje & J.Castro (2021), 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
  • Family: Zamiaceae, order Cycadales
  • Common names: no name attested, in English or in any other language
  • Natural range: Colombia, Caldas department (municipality of La Dorada), a single known locality, 200 to 245 m
  • IUCN status: Not Evaluated; Critically Endangered (CR) recommended by its authors in 2021
  • 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 (see Cold hardiness)
  • Light and soil: in the wild, fairly open forest understorey with moderate light, on sandy, free-draining, acid soil rich in organic matter; no published growing advice for the species
  • Habit and adult size: underground stem 10 to 30 cm long; 1 to 5 leaves, 58 cm to 2 m long in adult plants, with small leaflets 4 to 12 cm long
  • In the UK, US and Australia: no garden record
  • Toxicity: no data specific to the species; treat it as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Zamia imbricata

Zamia imbricata is recognised by leaves that look flat: the straight rachis is held almost horizontally and carries many small, thin leaflets, toothed towards the tip, which overlap strongly. The petiole is smooth or bears only a few minute prickles. The description below follows the original publication (Calonje and colleagues, 2021):

  • Stem: underground, usually solitary, cylindrical, 10 to 30 cm long; deciduous, triangular cataphylls 3.2 to 5.2 cm long, covered in tawny down.
  • Leaves: 1 to 5 per plant, 13 cm to 2 m long (at least 58 cm in adult plants), covered in white to beige down as they emerge, then hairless. The petiole, 34 to 141 cm long in adults, ochre to olive green, is usually unarmed, rarely with a few translucent prickles 0.5 to 0.8 mm long; the rachis, 24 to 73 cm long, is unarmed.
  • Leaflets: 6 to 110 (at least 40 in adults), lanceolate, thin (membranous), dark green and matt to slightly glossy above, pale green beneath, strongly imbricate and held in a single plane; the margin bears 5 to 25 teeth 1 to 2.5 mm long on the outer half. Middle leaflets measure 4.9 to 11.6 cm by 1.5 to 1.8 cm.
  • Male cones: 1 or 2, light reddish brown, 2.8 to 3 cm by 0.7 to 0.8 cm when shedding pollen, on a very long stalk of 20 to 25 cm.
  • Female cones: solitary, reddish brown to brown, cylindrical, 5.2 to 8.8 cm by 2.8 to 4 cm, on a stalk of 25 to 31.5 cm; scales with a flat outer face.
  • Seeds: ovoid, 13 to 13.6 mm by 9.2 to 9.6 mm, with a very thin, orange-red fleshy coat (sarcotesta).

Hybrids

No hybrid is known. Zamia imbricata grows at the same site as Zamia incognita, but the authors of the description saw no intermediate forms: every plant they examined clearly belonged to one species or the other. They put forward several possible explanations without choosing between them: different pollinators, incompatibility between two distantly related lineages, or reproductive seasons that do not overlap.

Possible confusion

On site, confusion with Zamia incognita is unlikely, since that species has large, broad, obovate, glossy leaflets 30 to 40 cm long. The original description compares the species mainly with two close relatives:

  • Zamia “Cogollo”, a still undescribed species from the municipality of Puerto Berrío (Antioquia), about 75 km away: separate, linear-lanceolate leaflets (more than seven times longer than wide), up to 25 cm long, with a prominent lengthwise fold; leaves up to 2.5 m long; a sterile tip of more than 1.5 cm on the female cone. In Zamia imbricata the leaflets are imbricate, lanceolate (less than seven times longer than wide), up to about 10 cm long and not folded, and the sterile tip of the female cone is under 1 cm.
  • Zamia vazquezii, from Mexico, also has short, broad, thin leaflets, but they are not held in a single plane, its cone stalks are much shorter (under 10 cm) and its male cone scales carry more pollen sacs (18 to 22, against 9 to 11).

Taxonomy

Zamia imbricata is an accepted name according to The World List of Cycads and GBIF; POWO could not be consulted directly. The species has no synonym. It was described in 2021 by Michael Calonje and Jonatan Castro Hernández, with Luis Fernando Coca, Daniel Jaramillo and Arturo Aristizábal, in the journal Phytotaxa (volume 497, pages 1 to 19), in a paper that also describes Zamia sinuensis, from the Sinú valley (Córdoba).

The authors place both species in the “manicata clade”, a group of species from northern Colombia and eastern Panama whose relationship is well supported by molecular analyses (Calonje and colleagues, 2019, cited in the 2021 paper). The group comprises Zamia manicata, Zamia disodon, Zamia melanorrhachis and Zamia restrepoi (formerly Chigua restrepoi), plus the two species described in 2021 and Zamia “Cogollo”. Their leaflets are extraordinarily varied, but they share an underground stem, strongly toothed leaflets, cones on very long stalks (usually more than 20 cm), cone scales with a flat face, small seeds with a very thin coat and tiny male cones. According to the authors, Zamia imbricata and Zamia “Cogollo” are the southernmost species of the group.

The transcriptome phylogeny of Lindstrom and colleagues (2024) did not sample Zamia imbricata. The authors confirm a northern Colombian subgroup made up of Zamia restrepoi, Zamia disodon, Zamia manicata and Zamia sinuensis, the assemblage called the Manicata clade by Calonje and colleagues, and consider that Zamia imbricata and Zamia melanorrhachis probably belong to it on the strength of shared morphological characters; this remains to be confirmed by sequencing.

Etymology and history

The epithet imbricata comes from the Latin imbricatus, “covered with tiles”, and describes the strongly overlapping leaflets (original description; Haynes, 2022, as given by The World List of Cycads).

According to its authors, the species was found during recent surveys of the moist forests of the Magdalena-Urabá region, long little explored because of the violence that affected the area for more than half a century. Specimens had been collected at La Dorada in December 2018 and March 2019; the authors, associated with the Colombian Cycad Society (Sociedad Colombiana de Cycadas), studied the population in the field in February 2020. The holotype, collected on 17 February 2020 at 244 m by Jonatan Castro, Michael Calonje, Luis Fernando Coca and Daniel Jaramillo (no. 1601), is kept at the herbarium of the University of Antioquia (HUA), with an isotype at the herbarium of the University of Caldas (FAUC). Precise localities have not been published, to limit the risk of illegal collecting.

Common names

No common name is attested for this species, in English or in Spanish.

In the wild

Zamia imbricata is known only from a forest fragment of about 1 km² in the municipality of La Dorada, at the eastern foot of the Cordillera Central, in the Magdalena basin. It grows on steep slopes in tropical moist forest between 200 and 245 m. The soil is sandy, free-draining, rich in organic matter and leaf litter, acid (pH 4.5 to 5), high in aluminium, iron and manganese, and poor in phosphorus, calcium, potassium and sodium. The canopy is 9 to 35 m tall, and the fairly open understorey lets in moderate light (Calonje and colleagues, 2021).

Climate. The climate is equatorial (Af in the Köppen classification): a mean annual temperature of 27 °C (80.6 °F) and about 2,500 mm of rain a year, falling in two rainy seasons that peak in April and October. The driest month, January, still receives 50 mm, the wettest, October, 314 mm.

Biology. Almost nothing is known of its biology. In February 2020 the male cones were one or two weeks from shedding pollen, and the nearly ripe female cones had remained largely unpollinated. The pollinator has not been identified; in Zamia incognita, which shares the site, it is a beetle of the genus Pharaxonotha. A few leaves showed damage by herbivores, but the insect responsible was not seen.

Conservation status and regulation

Zamia imbricata has not yet been assessed by the IUCN (The World List of Cycads, version 2026.08.15; GBIF gives the same status, Not Evaluated, queried on 25 October 2026). Its authors recommend listing it as Critically Endangered (CR) under criteria B1ab(iii,v)+2ab(iii,v), C2a(i,ii) and D: after four days of searching they found only fifteen plants and no living seedling, only the remains of a dead one. Seed production was very low, with a single pollinated ovule in two female cones. In their view the plants are too few or too scattered to sustain a viable population, and no recruitment is taking place. This preliminary assessment has no official standing (Calonje and colleagues, 2021).

Like all Zamia except Zamia restrepoi, which is in Appendix I, Zamia imbricata is covered by the listing of the genus in CITES Appendix II, in force since 4 February 1977. Annotation #4 exempts in particular seeds, pollen, seedlings or tissue cultures obtained in vitro and transported in sterile containers, and cut flowers of artificially propagated plants; international trade in the plants themselves requires an export permit. 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+ does not yet name the species, but the listing covers the whole genus (“Zamia spp.”) and therefore includes it (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, ask the seller for proof of origin and prefer plants raised from cultivated seed.

Growing Zamia imbricata

No growing advice specific to Zamia imbricata has been published and no cultivation is documented: the species, described in 2021 and known from about fifteen plants, does not appear to be in cultivation. Simon Lavaud, of the French specialist nursery Cycadales.eu, nevertheless lists it among the Zamia of the lowland forests of Central and South America, a group he rates as difficult outside the tropics because European climates are generally too cool and too dry for them (Lavaud, 2023).

Its habitat gives a few pointers: constant warmth (a mean of 27 °C, 80.6 °F), abundant rain with no real dry season, sandy acid soil and partial shade. A heated glasshouse, a very free-draining compost kept lightly moist all year and protection from direct sun would be the most consistent approach, but this has not been tested in any published trial.

Outdoor and in-ground cultivation

Outdoor cultivation is only conceivable in a frost-free, humid tropical climate, and no planting has been reported anywhere.

Container cultivation

In temperate climates any plant would need a heated glasshouse or a bright, heated interior. For the lowland group to which he assigns the species, Lavaud (2023) recommends a glasshouse, conservatory, well-lit heated room or even an indoor growing chamber, since these Zamia tend to suffer from a lack of warmth even in summer in northern Europe.

In cultivation in the UK, US and Australia

In short: no record in any of the three countries.

  • United States: no record in BGCI or in the online catalogue of Montgomery Botanical Center (both queried on 25 October 2026).
  • United Kingdom: no record in BGCI or in the online catalogues of British gardens.
  • Australia: no record in BGCI or in the online catalogues of Australian gardens.

Propagation

No data specific to the species. Like all Zamia, it has separate male and female plants, and it would be propagated from fresh seed. In the wild, a seed taken from a cone finished ripening two months after the cone was collected (Calonje and colleagues, 2021). Given the rarity of the species, collecting seed in the wild is unacceptable.

Pests and diseases

No pest or disease specific to the species has been documented. In the wild, a few leaves bore traces of unidentified herbivores. In cultivation, Zamia are chiefly at risk from rot in cold, waterlogged compost and from scale insects.

Cold hardiness

No data exist on the cold tolerance of Zamia imbricata. It lives at low elevation under an equatorial climate with a mean annual temperature of 27 °C (80.6 °F) and no cold season; nothing suggests that it tolerates frost.

Mediterranean and European experience

No cultivation has been reported in France or elsewhere in Europe, either in the ground or in a pot, and no dated frost episode concerns the species. For readers in Mediterranean-type climates such as California or southern Australia, it remains a plant for heated glass.

United Kingdom, United States and Australia

No cold record exists, since the species is not known in cultivation. In the UK it could only be grown in a heated glasshouse.

Toxicity and precautions

No toxicity study specific to Zamia imbricata has been published. The risk is, however, well documented in cycads: Zamia contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, a compound toxic to the liver and nervous system, and the ASPCA cites cycasin and BMAA, a neurotoxic amino acid, for Zamia furfuracea, which it lists as toxic to 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 use is documented for this species.

Frequently asked questions

What does the name Zamia imbricata mean?

“Covered with tiles”. The Latin epithet describes the small leaflets, which overlap strongly like the tiles of a roof.

Where does it grow?

Only at La Dorada, in the Caldas department of Colombia, in a fragment of moist forest of about 1 km², between 200 and 245 m.

Is it endangered?

Very probably, yes. The IUCN has not yet assessed it, but its authors recommend listing it as Critically Endangered: fifteen known plants, no seedlings and very few seeds.

How can it be told from Zamia incognita, which grows at the same site?

Easily. Zamia incognita has large, broad, glossy leaflets 30 to 40 cm long; Zamia imbricata has small, thin leaflets 4 to 12 cm long, closely overlapping in a single plane. No hybrid has been observed.

Is it related to Zamia manicata and Zamia restrepoi?

Probably. Its authors place it in the manicata clade of northern Colombia, and the 2024 transcriptome study, which did not sample it, considers it likely to belong to that group on morphological grounds.

Is it hardy?

In all likelihood, no. No cold data exist, and it lives under an equatorial climate with no cold season; it is a plant for a heated glasshouse.

Can it be bought?

In practice, no. The species does not appear to be in cultivation. It is covered by CITES Appendix II; seeds are exempt under annotation #4, but the species is so rare that no collecting in the wild can be justified.

Is it poisonous?

It must be assumed so. No analysis specific to the species exists, but the cycads studied contain serious toxins, mainly in the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Calonje, M., Castro Hernández, J., Coca, L.F., Jaramillo, D. & Aristizábal, A. (2021). Two new species of Zamia (Zamiaceae, Cycadales) from the Magdalena-Urabá moist forests ecoregion of northern Colombia. Phytotaxa 497(1): 1–19. https://doi.org/10.11646/phytotaxa.497.1.1 [Original description; 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 [Species not sampled; probable membership of the northern Colombian subgroup discussed; full text consulted.]
  • Calonje, M., Meerow, A.W., Griffith, M.P., Salas-Leiva, D., Vovides, A.P., Coiro, M. & Francisco-Ortega, J. (2019). A time-calibrated species tree phylogeny of the New World cycad genus Zamia L. (Zamiaceae, Cycadales). International Journal of Plant Sciences 180(4): 286–314. https://doi.org/10.1086/702642 [Phylogeny of the genus; not consulted directly, cited by the papers read.]
  • 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.]