Zamia hymenophyllidia

Zamia hymenophyllidia is a small cycad of the lowland Amazon rainforest, in southern Colombia (Amazonas) and north-eastern Peru (Loreto). This species of the genus Zamia, described in 2001, takes its name from its thin, almost translucent leaflets; long described as stemless, it does in fact sometimes form a slender trunk. The IUCN rates it Least Concern, one of the few Zamia not considered threatened.

Key facts about Zamia hymenophyllidia

  • Accepted name: Zamia hymenophyllidia D.W.Stev. (2001), 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: Colombia (Amazonas: Tarapacá, La Chorrera, La Pedrera, Leticia, Puerto Nariño) and Peru (Loreto)
  • IUCN status: Least Concern (LC), 2022 assessment
  • 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: understorey of lowland Amazon forest, at about 95 to 250 m (herbarium collections); grown in a tropical glasshouse at Nong Nooch (Thailand)
  • Habit and adult size: usually without a visible stem; sometimes a slender stem up to 40 cm tall and 7 cm across; 3 to 15 leaves
  • In the UK, US and Australia: no record in BGCI or in the online catalogue of Montgomery Botanical Center
  • Toxicity: no data specific to the species; treat it as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Zamia hymenophyllidia

The clearest character is the texture of the leaflets: membranous, thin and almost transparent. According to the comparisons published by Segalla and colleagues (2023) and Calonje and colleagues (2026), the median leaflets, elliptic with a long, tapering tip, measure 16 to 24 cm by 4.5 to 7.2 cm; they carry 0 to 11 teeth, only in the upper half, and 21 to 28 veins, moderately raised on the upper surface (very clearly so when dry). A raised longitudinal fold runs along the upper surface. The new leaves emerge green.

The plants carry 3 to 15 leaves. Described in 2001 as a species with an underground stem, it does sometimes form a slender aerial stem: most plants seen at Leticia in 2017 and 2022 had no visible stem, but a few had a stem 12 cm tall and 4 cm across, and herbarium collections record stems up to 40 cm tall and 7 cm in diameter. The scales of the male cones carry 10 to 12 sporangia, and the cones are borne on long stalks.

The original description (Stevenson, 2001, Flora de Colombia) gave much smaller figures: an underground, tuberous stem 2 to 4 cm in diameter; 2 to 5 erect leaves 30 to 70 cm long; 4 to 10 pairs of elliptic to elliptic-lanceolate leaflets 12 to 15 cm long and 1 to 2 cm wide, with an entire margin or rarely a few tiny teeth near the tip; brown male cones 1 to 3 cm long on stalks 10 to 15 cm long; dark reddish brown female cones up to 5 cm long and 3 to 4 cm wide on a stalk up to 15 cm; and red-orange seeds 1 to 1.2 cm long. The measurements published in 2023 and 2026, based on other collections and on cultivated plants, are much larger for the leaflets; the two sets of figures should be read together.

Hybrids

No hybrid has been documented.

Possible confusion

The original description considers it closest to Zamia melanorrhachis, of Colombia: both species have extremely long stalks, up to 30 cm, ending in tiny male cones, but Zamia melanorrhachis has papery, lanceolate, usually acute and clearly toothed leaflets and, in life, a dark purple to black petiole and rachis (Stevenson, 2001). The same work notes that Zamia disodon, also from Colombia, is the only other species with membranous leaflets, but its leaflets are doubly toothed.

Three Amazonian species also resemble it; their ranges are hundreds of kilometres apart:

  • Zamia multidentata, of Acre (Brazil), described in 2023: also with a slender stem, but papery to cartilaginous leaflets with 30 to 49 teeth and 36 to 47 veins;
  • Zamia urarinorum, of the swamp forests of Loreto (Peru), described in 2026: cartilaginous to leathery leaflets with more teeth (10 to 41), including in the lower half;
  • Zamia urep, of Peru: stemless, flat leaflets without a longitudinal fold, with very prominent veins, and yellowish brown new leaves.

Taxonomy

Zamia hymenophyllidia is an accepted name according to The World List of Cycads and GBIF; POWO could not be consulted directly. The species was described by Dennis W. Stevenson in 2001 in the treatment of the Cycadales in the Flora de Colombia (volume 21), with a short Latin diagnosis comparing it with Zamia melanorrhachis. The type specimen (D. Cárdenas et al. 10089) was collected on 11 March 1999 at Tarapacá (Amazonas, Colombia), at 200 m; the holotype is kept at the Colombian Amazon herbarium (COAH), with an isotype in New York (NY). The name has not changed.

What has changed is the understanding of the plant. In 2023 Rosane Segalla, Ricardo Pimenta and Michael Calonje, describing Zamia multidentata, showed that Zamia hymenophyllidia can form an aerial stem. With Zamia poeppigiana, Zamia multidentata and Zamia urarinorum, it is one of the four trunk-forming species among the eleven Zamia known from the Amazon basin in 2026. Its precise relationships with these species have not been established.

In molecular studies, an earlier phylogeny (Calonje and colleagues, 2019, as summarised by Lindstrom and colleagues, 2024) had placed Zamia amazonum with Zamia urep and Zamia hymenophyllidia, with weak support; the transcriptome phylogeny of Lindstrom and colleagues (2024), which included a sample from Loreto, did not recover that grouping, placing Zamia amazonum instead with Zamia ulei.

Etymology and history

The epithet is formed from the Greek hymen, “membrane”, and phyllon, “leaf”, and refers to the thin, almost transparent leaflets (Stevenson, 2001; Haynes, 2022, as given by The World List of Cycads). Among the collections cited in recent work is a specimen gathered by Richard Evans Schultes and G.A. Black in September 1946 in the Colombian Amazonas, more than fifty years before the species was described. In 2001 Stevenson noted that it had been discovered only recently.

Common names

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

In the wild

The collections examined by Segalla and colleagues (2023) and Calonje and colleagues (2026) come from the south of the Colombian Amazonas (Tarapacá, La Chorrera, La Pedrera, Leticia, Puerto Nariño) and from Peruvian Loreto, between 94 and 250 m. The World List of Cycads places the species in Colombia (Amazonas) and Peru (Loreto). Field studies were devoted to it at Leticia and Puerto Nariño in November 2017 and January 2022, with the support of the Colombian Cycad Society and the National University of Colombia.

Simon Lavaud, of the French specialist nursery Cycadales.eu, quotes the climate of Iquitos, in Peru, where several Zamia grow, including this one: night-time minima of 23 °C (73.4 °F), daytime maxima of 30 °C (86 °F), 2,900 mm of rain a year and air humidity of 88 to 91 per cent (Lavaud, 2023).

Conservation status and regulation

Zamia hymenophyllidia is rated Least Concern (LC) on the IUCN Red List, in the 2022 assessment by Cristina López-Gallego and Michael Calonje (The World List of Cycads; GBIF gives the same category; the Red List itself could not be consulted): it is one of the few Zamia species not considered threatened. In 2001 the original description reported three small populations found shortly before, which were producing seeds and seedlings, and judged the species probably rare given how few collections existed.

Like all Zamia except Zamia restrepoi, Zamia hymenophyllidia falls under CITES Appendix II, where the genus has been listed since 4 February 1977. International trade in live plants is therefore allowed, but requires an export permit from the country of origin. The listing carries annotation #4: seeds, pollen, and seedlings or 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 hymenophyllidia

The species is grown at Nong Nooch Tropical Botanical Garden, at Chonburi (Thailand), which holds a reference living collection of cycads: Segalla and colleagues (2023) studied two plants there (accession numbers 16022A and 16027A), one of them from Peruvian Loreto.

Lavaud (2023) places it among the Zamia of the lowland forests of South America, which he rates difficult outside the tropics: European climates are too cool and too dry for them, even in high summer, and he recommends a glasshouse, conservatory, bright heated room or growth chamber. For this group he advises:

  • 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);
  • high air humidity, between 70 and 90 per cent.

He illustrates the species among the lowland Colombian Zamia that are reputed difficult to grow. These are recommendations for a group of species, not measurements made on Zamia hymenophyllidia.

Outdoor and in-ground cultivation

Outdoor cultivation is only conceivable in a humid equatorial climate, without a cool season. No outdoor planting is known outside its range and Thailand.

Container cultivation

Its small size makes it suitable for a pot in a heated glasshouse: shade, constant warmth by night as well as by day, high humidity and a free-draining, neutral to acid compost kept moist, following the advice above for the lowland group. No grower’s account specific to the species has been published.

In cultivation in the UK, US and Australia

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

  • United States: no accession in the online catalogue of Montgomery Botanical Center, and no American garden declares it to BGCI (both queried on 25 October 2026).
  • United Kingdom: no record in BGCI.
  • Australia: no record in BGCI.

The only documented cultivated plants are those at Nong Nooch, in Thailand (Segalla and colleagues, 2023). The British nursery Trebrown lists the species with a cold hardiness zone of 10a, a commercial rating with no stated basis.

Propagation

No data specific to cultivation. Like all Zamia, the species has separate male and female plants and is propagated from seed of fertilised plants; in 2001 the wild populations were producing seeds and seedlings (Stevenson, 2001).

Pests and diseases

No pest or disease has been documented.

Cold hardiness

No data exist on the cold tolerance of Zamia hymenophyllidia. It is a species of the Amazonian lowlands, under an equatorial climate with no cool season, where night temperatures stay around 23 °C (73.4 °F) (Lavaud, 2023).

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; on the French Fous de palmiers forum it appears only once, in a travel account (2012). Lavaud (2023), who grows cycads in Montpellier, stresses that even in July and August, nights around 19 °C (66.2 °F) are below what these lowland species need. For readers in Mediterranean-type climates such as California or southern Australia, as in the UK, it remains a plant for a heated glasshouse.

United Kingdom, United States and Australia

No cold record exists. The zone 10a given by Trebrown is a commercial rating and should not be taken as a measured limit; in practice the species needs heated glass all year in the UK.

Toxicity and precautions

No toxicity study specific to Zamia hymenophyllidia 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

What does “hymenophyllidia” mean?

“With membranous leaves”, from Greek: its leaflets are thin and almost transparent.

Where does it grow?

In the lowland Amazon forest of southern Colombia (Amazonas) and north-eastern Peru (Loreto), at about 95 to 250 m.

Does it have a trunk?

Sometimes. Most plants have no visible stem, but some form a slender stem up to 40 cm tall and 7 cm across.

How can it be told from Zamia melanorrhachis?

By its membranous, elliptic leaflets with few or no teeth, whereas Zamia melanorrhachis has papery, toothed leaflets and a dark purple to black petiole and rachis (Stevenson, 2001).

Is it endangered?

No: it is one of the few Zamia rated Least Concern (LC) by the IUCN (2022).

Can it be grown?

Yes, but only in a heated tropical glasshouse; it is grown at Nong Nooch, in Thailand. No cold data exist, and live plants travel with CITES permits.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Stevenson, D.W. (2001). Orden Cycadales. Flora de Colombia 21: 1–91. [Treatment of the cycads of Colombia and protologue of the species (pp. 43–47, figs 6–7); digitised text consulted.]
  • Segalla, R., Pimenta, R.S. & Calonje, M. (2023). Zamia multidentata (Cycadales, Zamiaceae), a new arborescent species of Zamia from Acre, Brazil. Phytotaxa 598(1): 21–31. https://doi.org/10.11646/phytotaxa.598.1.2 [Detailed comparison with Zamia hymenophyllidia; full text consulted.]
  • Calonje, M., Zárate-Gómez, R., Jones, M.A., Segalla, R., Martín Brañas, M., Hidalgo Pizango, C.G. & Roca Alcázar, F. (2026). Zamia urarinorum (Cycadales, Zamiaceae), a new cycad species from wetland forests of Loreto, Peru. Phytotaxa 741(1): 1–17. https://doi.org/10.11646/phytotaxa.741.1.1 [Comparison table including Zamia hymenophyllidia; full text 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 Loreto; discussion of the earlier grouping with Zamia amazonum and Zamia urep; full text consulted.]
  • Lavaud, S. (2023). Comment cultiver les Zamia en climat tempéré. Cycadales.eu. [Growing advice for groups of species; read directly.]
  • López-Gallego, C. & Calonje, M. (2022). Zamia hymenophyllidia. The IUCN Red List of Threatened Species 2022: e.T42110A69833688. [Assessment cited by The World List of Cycads; Red List page not consulted.]
  • 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.]