Zamia lawsoniana

Zamia lawsoniana is a cycad of south-eastern Mexico, known from southern Veracruz, northern Chiapas and Tabasco, and possibly Oaxaca, where it grows from sea level to 840 m in oak woodland and secondary tropical forest. Described in 1884, this species of the genus Zamia was then sunk into Zamia loddigesii for almost thirty years, before being reinstated in 2024. It is recognised by its narrow, leathery leaflets and by the very long stalks of its cones. The IUCN has not yet assessed it; the botanists who reinstated it consider it Endangered.

Key facts about Zamia lawsoniana

  • Accepted name: Zamia lawsoniana Dyer (1884), accepted by The World List of Cycads (version 2026.08.15) since its reinstatement in 2024; POWO could not be consulted directly, and the World Checklist of Vascular Plants on which it is based still treats the name as a synonym of Zamia loddigesii
  • Former names and synonyms: treated as a synonym of Zamia loddigesii from 1995 to 2024, a treatment still followed by Species+
  • Family: Zamiaceae, order Cycadales
  • Common names: no English name; “pozol agrio” in Mexico (Nicolalde-Morejón and colleagues, 2024)
  • Natural range: Mexico, southern Veracruz, northern Chiapas, Tabasco, perhaps Oaxaca (type locality); from sea level to 840 m
  • IUCN status: Not Evaluated; Endangered (EN) proposed by the authors of 2024
  • 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, oak woodland, old fields (“acahuales”) and secondary growth of evergreen tropical forest; no published growing advice
  • Habit and adult size: underground stem up to 60 cm long and 18 cm across, branching with age; 2 to 5 leaves (up to 14), 66 to 163 cm long
  • In the UK, US and Australia: no garden declares the name; plants may be grown under Zamia loddigesii
  • Toxicity: no data specific to the species; treat it as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Zamia lawsoniana

Four characters taken together identify it: upright leaves whose petiole and rachis are slightly twisted, linear, leathery leaflets finely toothed in their last third, a petiole covered in 40 to 80 fine prickles, and cones carried on stalks much longer than themselves. The description below follows Nicolalde-Morejón and colleagues (2024):

  • Stem: underground, splitting in two with age, up to 60 cm long and 18 cm in diameter; persistent cataphylls with a long point (up to 8.4 cm), covered in yellowish down.
  • Leaves: 2 to 5 (up to 14), upright, 66 to 163 cm long, light green as they emerge, then green; petiole 18 to 52 cm, slightly twisted (straight in young plants), covered in fine prickles up to 3.4 mm long; rachis 32 to 66 cm, armed in its lower third.
  • Leaflets: 16 to 32 pairs, stalkless, leathery, linear and channelled, with a long, sharp tip; margin slightly rolled, finely toothed in the last third (up to nine teeth on each side); the middle leaflets measure 21.7 to 39 cm by 0.65 to 1.46 cm.
  • Male cones: 1 to 3, upright, cylindrical, 4.8 to 6 cm long and 1.4 to 1.7 cm across, pale yellow and finely downy, on a stalk 19 to 32 cm long, up to six times the length of the cone.
  • Female cones: 1 or 2, usually single, upright, cylindrical, 5 to 14 cm long and 3.5 to 5.6 cm across, light brown, with a sharp sterile tip; stalk 10 to 25 cm, up to twice the length of the fertile part.
  • Seeds: ovoid, up to 1.8 by 1 cm; fleshy coat pink before ripening, red when ripe.

Hybrids

No hybrid, natural or raised in cultivation, is documented.

Possible confusion

Zamia lawsoniana looks most like three narrow-leaved Mexican species, and it was long confused with the first of them. The key published in 2024 separates them as follows:

  • Zamia loddigesii, of the Gulf of Mexico coastal plain from Tamaulipas to Veracruz: middle leaflets lanceolate, at least 1.8 cm wide; petiole and rachis not twisted; female cones cream to yellowish, on a short stalk. Some plants from disturbed habitats have narrow leaflets, but their rachis remains straight;
  • Zamia spartea, from a small area of the Isthmus of Tehuantepec (Oaxaca), between 200 and 400 m, in tropical deciduous forest: similar foliage, but reddish brown new leaves, only 20 to 40 prickles on the petiole, and brown cones on short stalks;
  • Zamia stenophyllidia, from Michoacán: thin, papery leaflets and ovoid, yellowish brown female cones;
  • Zamia lawsoniana itself: light green new leaves, at least 60 prickles on the petiole, and female and male cone stalks up to two and six times the length of the cone respectively.

Three other Zamia grow in Tabasco: Zamia katzeriana, with oblong to oblanceolate leaflets that are glossy pinkish red when new; Zamia cremnophila, with lanceolate leaflets and reddish brown new leaves, on limestone rock; and Zamia prasina, with leaflets more than 4 cm wide.

Taxonomy

Zamia lawsoniana is an accepted name according to The World List of Cycads; POWO could not be consulted directly. The species was described in 1884 by William Turner Thiselton-Dyer in the Biologia Centrali-Americana (Botany, volume 3, page 195). The original description covered only the male cone, with its very long stalk, and gave only Oaxaca as the origin; the female cone was unknown.

For lack of sufficient characters, the name was placed in the synonymy of Zamia loddigesii in 1995 (Stevenson and colleagues), a treatment followed by the revision of Mexican Zamia in 2009. In 2024 Fernando Nicolalde-Morejón, Lilí Martínez-Domínguez, Marlon Aramis González-Aguilar and Dennis Wm. Stevenson reinstated the species in Acta Botanica Mexicana (volume 131, e2262). They studied fifteen populations previously assigned to Zamia loddigesii (three in Tabasco, ten in Veracruz and two in Oaxaca), measured 153 female and 103 male cones in the field and followed the phenology through 2022 and 2023. The populations of the border area between south-eastern Veracruz, north-eastern Chiapas and Tabasco match the holotype of Zamia lawsoniana, with its twisted petiole and rachis and very long male cone stalk. They also described the female cone for the first time.

Not every database has caught up. Species+, which follows CITES nomenclature, still lists the name as a synonym of Zamia loddigesii (consulted on 3 October 2026), which makes no difference to regulation since the whole genus is in Appendix II. The World Checklist of Vascular Plants, the Kew list on which POWO is based, read on GBIF (version of 4 June 2026), also still gives Zamia lawsoniana Dyer as a synonym of Zamia loddigesii Miq. The site follows The World List of Cycads, the checklist of the IUCN Cycad Specialist Group, which accepts the reinstatement. In practice, plants once grown or labelled as Zamia loddigesii that came from Tabasco or southern Veracruz may belong to Zamia lawsoniana.

Etymology and history

The epithet honours the naturalist John Lawson, who collected several specimens of the species (Nicolalde-Morejón and colleagues, 2024, as given by The World List of Cycads).

The type, collected in Oaxaca under the number Fielding 209, is kept at the University of Oxford (holotype, OXF), with an isotype at Kew (K). According to the authors of 2024, no population with these characters has yet been found in south-eastern Oaxaca, but the species may occur there: the region has been heavily deforested, mainly for cattle ranching, and new surveys in the Uxpanapa-Chimalapas area could reveal populations.

Common names

There is no English name. In Mexico the species is called “pozol agrio” (Nicolalde-Morejón and colleagues, 2024), a name the authors give without explanation; no other name is attested.

In the wild

Zamia lawsoniana is endemic to Mexico. The specimens examined in 2024 come from Tabasco (the municipalities of Huimanguillo and Macuspana), southern Veracruz (Las Choapas and Moloacán) and northern Chiapas (Juárez, and Ocozocoautla at 840 m). The species grows from sea level to 840 m, in oak woodland, old fields (“acahuales”) and the secondary growth of evergreen tropical forest, alongside gumbo-limbo (Bursera simaruba), Mimosa pigra, the palm Acoelorraphe wrightii, figs and Pseudobombax ellipticum.

New leaves appear in flushes of one to three. Female cones are receptive from June to August, ripen in November and December and break up from January to March; male cones shed pollen from April to early October.

Conservation status and regulation

Zamia lawsoniana, reinstated in 2024, has not yet been assessed by the IUCN (The World List of Cycads, version 2026.08.15). The botanists who reinstated it propose classing it as Endangered (EN) under criteria A1acd and B1ab(iii,iv). Most populations are in disturbed areas given over to extensive cattle ranching; the evergreen tropical forest of the coastal plain of southern Veracruz and Tabasco has been heavily cleared; natural regeneration is rare in Tabasco and Veracruz. Only one population, in northern Chiapas, is in good condition, and none lies within a protected area. This preliminary assessment has no official standing.

Like all Zamia except Zamia restrepoi, which is in Appendix I, Zamia lawsoniana is covered by the listing of the genus in CITES Appendix II, in force since 4 February 1977. Annotation #4 (the version adopted at CoP20, in force on 5 March 2026) exempts seeds, pollen, seedlings and 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. The listing covers the whole genus (“Zamia spp.”) and therefore this species, which Species+ still files under Zamia loddigesii, itself in Appendix II.

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 lawsoniana

No growing advice specific to Zamia lawsoniana has been published. Reinstated only in 2024, it may have been grown under the name Zamia loddigesii, but no source documents this.

Its habitat gives some pointers: low elevation, a hot tropical climate, and fairly open oak woodland and old fields. Growing it warm, in a free-draining compost, in light shade or filtered sun is the most consistent approach; it has not been validated by published trials.

Outdoor and in-ground cultivation

Planting out is only conceivable in a frost-free climate. Its lowland origin, from sea level to 840 m, suggests that it needs warmth all year; no garden is known to grow it outdoors under this name.

Container cultivation

In temperate climates it is a plant for a heated glasshouse or a bright, warm room. Its underground stem suits a deep pot, and its leaves, up to 1.6 m long, need room; as with all Zamia, the compost must drain well and never stay cold and wet.

In cultivation in the UK, US and Australia

In short: no garden in these three countries declares the name.

  • United States: no record under Zamia lawsoniana in BGCI. A search for the name in the online catalogue of Montgomery Botanical Center (Coral Gables, Florida) leads to its Zamia loddigesii entry, so any plants of this species held there would be filed under that name; the catalogue does not give their origin (consulted on 25 October 2026).
  • United Kingdom: no record in BGCI or in the online catalogues of British gardens.
  • Australia: no record in BGCI.

The only garden that declares Zamia lawsoniana to BGCI is the Francisco Javier Clavijero Botanic Garden in Xalapa, Mexico (queried on 25 October 2026). A BGCI declaration shows that a garden held the plant at some point, not that it is alive there today.

Propagation

No data specific to the species. Like all Zamia, it has separate male and female plants. In the wild, female cones are receptive from June to August, while male cones shed pollen from April to October, and the seeds ripen in November and December. It is propagated from fresh seed, handled with gloves.

Pests and diseases

No pest or disease specific to the species has been documented. In cultivation, Zamia are chiefly at risk from rot in cold, waterlogged soil and from scale insects.

Cold hardiness

No data exist on the cold tolerance of Zamia lawsoniana. It lives at low elevation in south-eastern Mexico, and no observation says whether it can take frost. The British nursery Trebrown places it in USDA zone 9b, a commercial classification without any dated record.

Mediterranean and European experience

No cultivation result has been published 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 should be kept frost-free until trials exist.

United Kingdom, United States and Australia

No cold record exists. Reports published under the name Zamia loddigesii cannot be attributed to it without knowing where the plants came from. In the UK it needs a heated glasshouse.

Toxicity and precautions

No toxicity study specific to Zamia lawsoniana 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. The local name “pozol agrio” is given without explanation by the authors of 2024.

Frequently asked questions

Is Zamia lawsoniana a new species?

No. It was described in 1884, but it was included in Zamia loddigesii from 1995 to 2024, when Mexican botanists reinstated it as a species.

Where does it grow?

In south-eastern Mexico: southern Veracruz, northern Chiapas and Tabasco, from sea level to 840 m; perhaps also in Oaxaca, where the type came from.

How can it be told from Zamia loddigesii?

By its linear leaflets less than 1.5 cm wide, its slightly twisted petiole and rachis, and the very long stalks of its cones; Zamia loddigesii has broader leaflets and cream to yellowish female cones on short stalks.

Why do some databases still call it Zamia loddigesii?

Because the reinstatement is recent. The World List of Cycads accepted it after 2024, but Species+ and the World Checklist of Vascular Plants, which underpins POWO, still list the name as a synonym of Zamia loddigesii.

What is its local name?

“Pozol agrio”, according to the authors of 2024. There is no English name.

Is it endangered?

Probably. The IUCN has not yet assessed it, but the botanists who reinstated it propose Endangered: cleared habitat, rare regeneration and no population in a protected area.

Is it hardy?

Nobody knows. No cold data exist; it comes from low elevations and should be grown frost-free.

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

  • 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 [Peer-reviewed article; full text read.]
  • Thiselton-Dyer, W.T. (1884). Cycadaceae. Biologia Centrali-Americana, Botany 3: 190–195. [Original description; cited after The World List of Cycads and the 2024 article.]
  • 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 [Revision of the genus in Mexico; cited after the 2024 article.]
  • 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.]