Zamia stenophyllidia

Zamia stenophyllidia is a small cycad of western Mexico, endemic to the state of Michoacán, where it grows in oak forest at about 450 to 675 m in the municipality of Arteaga. Described in 2019, this species of the genus Zamia was split from Zamia paucijuga, a very variable species of Mexico’s Pacific coast, from which it differs in its very narrow, thin leaflets, hence its name, “narrow-leaved”. Only two populations are known, and the IUCN has not yet assessed it.

Key facts about Zamia stenophyllidia

  • Accepted name: Zamia stenophyllidia Nic.-Mor., Mart.-Domínguez & D.W.Stev. (2019), 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 synonyms; before 2019 the Michoacán plants were included in Zamia paucijuga
  • Family: Zamiaceae, order Cycadales
  • Common names: none recorded, in English or in Spanish
  • Natural range: Mexico, state of Michoacán (municipality of Arteaga), two known populations, at about 450 to 675 m
  • IUCN status: Not Evaluated
  • 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, oak forest; in cultivation, a free-draining compost (group advice from Cycadales.eu)
  • Habit and adult size: two or three leaves 48 to 88 cm long, with 28 to 34 pairs of leaflets 29 to 36 cm by 6 to 8 mm; the stem has not been described in the sources available
  • In the UK, US and Australia: no record in botanic garden collections
  • Toxicity: no data specific to the species; treat it as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Zamia stenophyllidia

Look for few leaves, a straight petiole with only a handful of stout prickles, and numerous linear, very narrow, papery leaflets with finely toothed margins and long-drawn-out tips; the female cones are ovoid and yellowish. The summary of the original description singles out three characters: linear, papery leaflets no more than 0.8 cm wide, stout, short prickles no more than 2 mm long, and ovoid, yellowish female cones (Nicolalde-Morejón and colleagues, 2019). The measurements below come from the character tables published in 2024 (Nicolalde-Morejón and colleagues, 2024):

  • Leaves: two or three, upright, 48 to 88 cm long and 37 to 71 cm wide; petiole and rachis straight; two to six stout, short prickles on the petiole, which is covered in reddish-brown hairs; new leaves light green.
  • Leaflets: 28 to 34 pairs, linear and papery, with finely toothed (serrulate) margins and a long-acuminate tip; the median leaflets measure 29 to 36 cm by 0.6 to 0.8 cm and carry two to four teeth.
  • Male cones: two or three per plant, 7.5 to 10.5 cm long and 2.3 to 2.8 cm wide, on a peduncle 7.9 to 11.3 cm long.
  • Female cones: ovoid, yellowish, with an acuminate tip, 6 to 7.1 cm long and 5 to 6 cm wide, on a peduncle 3.8 to 4 cm long; 50 to 56 scales.

The stem is not described in the 2024 tables, and the full text of the 2019 description could not be read.

Hybrids

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

Possible confusion

The likeliest confusion is with Zamia paucijuga, from which it was separated, and with the other Mexican zamias with narrow leaflets. The 2019 revision recognised four species on the Pacific coastal plain of Mexico: Zamia paucijuga, Zamia herrerae, Zamia spartea and Zamia stenophyllidia (Nicolalde-Morejón and colleagues, 2019). A key published in 2024 separates them as follows (Nicolalde-Morejón and colleagues, 2024):

  • thin, papery leaflets: Zamia variegata (elliptic leaflets spotted with yellow), Zamia herrerae (lanceolate, toothed leaflets with an acute to acuminate tip) and Zamia stenophyllidia (linear, finely toothed leaflets with a long-acuminate tip);
  • leathery leaflets: Zamia spartea, of the Isthmus of Tehuantepec, with linear leaflets 3 to 6 mm wide, a twisted petiole armed with 20 to 40 fine prickles and reddish-brown new leaves; Zamia lawsoniana and Zamia loddigesii, of the Gulf of Mexico side, with 40 to 70 prickles on the petiole.

Against Zamia lawsoniana, the same authors also stress the shape and colour of the female cones: ovoid and yellowish in Zamia stenophyllidia, cylindrical and light brown in Zamia lawsoniana, whose leaflets are leathery rather than papery.

Taxonomy

Zamia stenophyllidia is an accepted name with no synonyms, according to The World List of Cycads and GBIF; POWO could not be consulted directly. It was described in 2019 by Fernando Nicolalde-Morejón, Lilí Martínez-Domínguez and Dennis W. Stevenson in the Nordic Journal of Botany (volume 37, article e02430), in a paper titled “Disentangling the identity of Zamia from Mexican Pacific seaboard, with a description of a new species”.

Until then the Michoacán populations had been included in Zamia paucijuga, a very variable species spread along about 1,200 km of the Pacific coastal plain, from Nayarit to Oaxaca, in habitats ranging from dry open woodland to deciduous forest and pine-oak forest. The authors revised all the Zamia populations of this coastal plain, comparing qualitative and quantitative morphological characters, and recognised in the Michoacán plants a distinct species, differing in both vegetative and reproductive structures. This meant redefining Zamia paucijuga, for which they designated an epitype, a supplementary reference specimen that fixes how the name is applied; they also published a key to all the Zamia of Mexico (Nicolalde-Morejón and colleagues, 2019; Nicolalde-Morejón and colleagues, 2024). In practice, plants from Michoacán labelled Zamia paucijuga in sources older than 2019 may belong to Zamia stenophyllidia.

The species has not yet been included in a published molecular phylogeny: the transcriptome study of Lindstrom and colleagues (2024) lists it among the accepted species that were not sampled.

Etymology and history

The epithet stenophyllidia comes from the Greek stenós, “narrow”, and phyllídos, “foliage” or “leaf”, and refers to the narrow leaflets (Haynes, 2022, followed by The World List of Cycads).

The type specimen was collected long before the species was named: in December 1987, by A. Pérez de la Rosa, in the municipality of Arteaga (Michoacán), at 600 m (number 1496). It is kept in the herbarium of the University of Guadalajara (IBUG) (The World List of Cycads). The authors’ team collected the species between 2014 and 2017 at El Guayabo (675 m) and Buena Vista (600 m), also in Arteaga (Nicolalde-Morejón and colleagues, 2024).

Common names

No common name is recorded for this species, in English or in Spanish. It is too recently described and too local to have acquired one.

In the wild

Zamia stenophyllidia is endemic to Michoacán, on the Pacific side of Mexico. Only two populations are known, both in the municipality of Arteaga. It grows in oak forest; the 2024 study gives an altitude of 450 to 600 m, but one of the specimens it cites was collected at 675 m (Nicolalde-Morejón and colleagues, 2024).

The authors of the description point out its biogeographical interest: it grows alongside Dioon stevensonii, a cycad that has served as a model for studying how modern Neotropical forests formed (Nicolalde-Morejón and colleagues, 2019). No data have been published on the local climate, pollinators, phenology or population structure.

Conservation status and regulation

Zamia stenophyllidia has not yet been assessed by the IUCN (The World List of Cycads, version 2026.08.15; GBIF gives the same status). With two known populations in a single municipality, its range is very small; whether the 2019 description proposed a conservation category is not known, as its full text could not be read.

Like all Zamia except Zamia restrepoi, which is in Appendix I, Zamia stenophyllidia 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+ 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, ask the seller for proof of origin, and prefer plants raised from cultivated seed.

Growing Zamia stenophyllidia

No growing advice specific to Zamia stenophyllidia has been published, and no cultivated plant is documented: no botanic garden declares it to BGCI, and it is absent from the online catalogue of Montgomery Botanical Center. Simon Lavaud, of the French specialist nursery Cycadales.eu, nevertheless lists 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 stenophyllidia.

Outdoor and in-ground cultivation

No outdoor planting has been documented anywhere. In frost-free regions, a sheltered spot in very free-draining soil, in the light shade that oak woodland suggests, would be the most consistent approach; it has not been validated by published trials.

Container cultivation

No container-growing report has been published. With two or three leaves under 90 cm long, the species is small enough to be kept in a pot, frost-free in winter and on the dry side, following the group advice above. This is a deduction, not a tested result.

In cultivation in the UK, US and Australia

None documented. No British, American or Australian garden declares Zamia stenophyllidia to BGCI, the online catalogue of Montgomery Botanical Center (Coral Gables, Florida) has no entry for it, and neither Trebrown, a British nursery that lists many cycads, nor the French nursery Cycadales.eu offers it (all checked on 25 October 2026). Plants grown before 2019 as Zamia paucijuga from Michoacán seed could belong to this species, but no collection has reported such a case.

Propagation

No data specific to the species. Like all Zamia, it has separate male and female plants and is propagated from fresh seed. With only two known populations, any collecting from the wild would be unacceptable.

Pests and diseases

No pest or 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 stenophyllidia. It lives below 700 m on the Pacific side of Mexico; no minimum temperature has been published for its habitat, and its response to frost is unknown.

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 kept frost-free until data exist.

United Kingdom, United States and Australia

No cold record and no commercial hardiness rating have been published. In the UK it would need a heated glasshouse in winter.

Toxicity and precautions

No toxicity study specific to Zamia stenophyllidia 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. 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 stenophyllidia mean?

“Narrow-leaved”. The name, built from Greek, refers to the very narrow leaflets, only 6 to 8 mm wide.

Is it a form of Zamia paucijuga?

No, not since 2019. The Michoacán plants used to be included in that very variable Pacific-coast species, but their papery, very narrow leaflets, stout prickles and yellowish female cones make them a distinct species.

Where does it grow?

Only in Mexico, in the municipality of Arteaga (Michoacán), in oak forest at about 450 to 675 m. Two populations are known.

How can I tell it from Zamia spartea?

By the texture of the leaflets and the petiole. Zamia stenophyllidia has thin, papery leaflets and a straight petiole with a few stout prickles; Zamia spartea has leathery, even narrower leaflets and a twisted petiole with many fine prickles.

Is it endangered?

Probably, but it has not been assessed. The IUCN has not yet examined it; with two known populations, its range is very small.

Can I buy it?

Not as far as published records show. No botanic garden declares it, and it does not appear in the catalogues of the specialist nurseries Trebrown and Cycadales.eu (checked on 25 October 2026); plants sold as Zamia paucijuga should not be assumed to be this species.

Is it poisonous?

It must be assumed so. No analysis concerns the species, but the cycads studied contain serious toxins, especially in the seeds.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Nicolalde-Morejón, F., Martínez-Domínguez, L. & Stevenson, D.W. (2019). Disentangling the identity of Zamia from Mexican Pacific seaboard, with a description of a new species. Nordic Journal of Botany 37(9): e02430, 1–11. https://doi.org/10.1111/njb.02430 [Original description; summary read through Crossref, full text not accessible.]
  • Nicolalde-Morejón, F., Martínez-Domínguez, L., González-Aguilar, M.A. & Stevenson, D.W. (2024). Reestablishment of Zamia lawsoniana (Zamiaceae, Cycadales), an endemic species of Mexico, with first description of the ovulate strobilus. Acta Botanica Mexicana 131: e2262. https://doi.org/10.21829/abm131.2024.2262 [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.]
  • 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.]