Zamia pseudomonticola

Zamia pseudomonticola is a cycad of the mountains of southern Costa Rica and western Panama, where it grows in the understorey of very wet and rain forests at middle elevations, mostly between 800 and 1,600 m, on the Pacific slope of the Talamanca range, in the Fila Costeña and in the Panamanian province of Chiriquí. This species of the genus Zamia looks so much like Zamia fairchildiana, its lowland neighbour, that its status has been debated ever since the Costa Rican botanist Luis Diego Gómez described it in 1982; the name was only validly published in 1986. The World List of Cycads accepts it, and the IUCN rates it Least Concern.

Key facts about Zamia pseudomonticola

  • Accepted name: Zamia pseudomonticola L.D.Gómez ex D.W.Stev. & Sabato (1986), 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; several authors have included it in Zamia fairchildiana, and plants of this species have circulated under that name
  • Family: Zamiaceae, order Cycadales
  • Common names: none attested, in English or in any other language
  • Natural range: Costa Rica (Puntarenas; also San José according to Acuña-Castillo, 2010) and Panama (Chiriquí); understorey of premontane and lower montane forest, 800 to 1,600 m
  • IUCN status: Least Concern (LC), assessment published in 2022
  • CITES and other protection: CITES Appendix II (listing of the family Zamiaceae; seeds exempt under annotation #4); Annex B in the European Union; zero export quota set by Panama for wild-collected specimens
  • Documented hardiness: no data (see Cold hardiness)
  • Light and soil: in the wild, the understorey of very wet to rain forest, on moderate to steep slopes; no growing advice specific to the species
  • Habit and adult size: trunk up to 2 m tall and 20 cm across, 6 to 18 leaves 80 to 250 cm long (Acuña-Castillo, 2010); the original description gave a trunk of only 30 cm
  • In the UK, US and Australia: Royal Botanic Gardens, Kew (BGCI); Montgomery Botanical Center (four accessions, 2001 to 2018) and two other American gardens; Royal Botanic Garden Sydney and Cairns Botanic Gardens
  • Toxicity: no data specific to the species; treat it as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Zamia pseudomonticola

On foliage alone it is hard to tell from Zamia fairchildiana; the best clues are its greenish cones on short stalks, leaflets with an entire margin near the tip, and the altitude at which it grows. The fullest description is the one in Ricardo Acuña-Castillo’s revision of the Zamia of Costa Rica (2010), a university thesis based on many specimens; it differs a good deal from the original description by Gómez (1982), which rested on a single specimen (see below).

Trunk and leaves

According to Acuña-Castillo (2010), adult plants have a cylindrical trunk, half buried or standing clear of the ground, up to 2 m tall and 20 cm across, with rough brown bark; Lindström and colleagues (2013) also speak of stems more than 2 m tall. The plant carries 6 to 18 leaves 80 to 250 cm long. The petiole, straight or slightly arched, is 29 to 95 cm long and the arched rachis 51 to 150 cm; both may be smooth or prickly. Each leaf has 10 to 40 pairs of leaflets. The middle leaflets, 16 to 33 cm long and 3 to 6 cm wide, four to seven times longer than broad, are lanceolate to sickle-shaped, asymmetric, smooth and glossy, with an entire margin, sometimes deeply notched; the tip is short (less than a fifth of the length), acute and fine.

For the Panamanian plants, Taylor Blake and Holzman (2012) describe a petiole and rachis clearly prickly up to the base of the rachis, leaflets with a marked lengthwise fold, almost entire, and a tip usually less than 3 cm long, against more than 3 cm in Zamia fairchildiana.

Cones and seeds

The species is dioecious. Male cones, almost cylindrical, measure 9.5 to 14 cm by 2.7 to 4.7 cm, on a downy brown stalk 8 to 10 cm long; their greenish-brown fertile scales bear pollen sacs on both faces, a feature shared with Zamia fairchildiana and rare in the genus (Lindström and colleagues, 2013). The female cone, borne singly and barrel-shaped, measures 10 to 35 cm by 8 to 11 cm, on a short stalk of 4 to 5 cm; its hexagonal scales are greenish, with a thin, scattered reddish-brown down (Acuña-Castillo, 2010). Lindström and colleagues (2013) describe it as hairless, dark green, with a short, blunt sterile tip and a stalk hidden among the cataphylls, whereas Acuña-Castillo (2010) gives it a long conical sterile tip, sometimes more than 3 cm. The seeds are “apricot-coloured” and almost spherical, 1.3 to 1.7 cm across, in the original description, orange to pinkish according to Acuña-Castillo (2010); Taylor and colleagues (2012), by contrast, write that all the Zamia of the isthmus have red seeds, except Zamia pseudoparasitica.

What the original description said

Gómez’s description (1982), based on the type specimen alone, depicts a much smaller plant: an upright trunk no more than 30 cm tall and 5 to 7 cm across; 3 to 10 leaves 80 cm to 1 m long with 9 to 14 pairs of opposite, elliptic-lanceolate, sickle-shaped and long-pointed leaflets, straight or curved back at the tip, entire, 15 to 22 cm by 3.5 to 4.5 cm; and, above all, a hairless petiole without prickles. The upright male cones measure 8 to 9.5 cm, on a stalk of 4 to 6 cm. Acuña-Castillo (2010) explains that this smooth petiole, true of the holotype, is very variable in the wild and in cultivation, even at the type locality: cultivated plants without prickles on their first leaves develop them years later. This detail did much to fuel the confusion with Zamia fairchildiana.

Hybrids

No hybrid has been demonstrated, but hybridisation with Zamia fairchildiana is suspected. According to L.D. Gómez, quoted by Acuña-Castillo (2010), it could occur in the foothills of the southern Fila Costeña, between 800 and 1,200 m, where some sterile specimens cannot be assigned with certainty to either species. Acuña-Castillo does not think it frequent, since the two species usually occupy different altitudes, and points out that only a genetic study could confirm it.

Possible confusion

The main source of confusion is Zamia fairchildiana. Acuña-Castillo (2010) gives these differences:

  • leaflets: lower margin entire near the tip in Zamia pseudomonticola, finely toothed in Zamia fairchildiana, whose tip also tapers more gradually;
  • mature male cones: under 14 cm long, against usually more than 20 cm;
  • female cones: stalk shorter than 5 cm and greenish scales, against a stalk of 5 cm or more and greyish scales;
  • altitude: mostly above 1,000 m, against mostly below 1,000 m for Zamia fairchildiana;
  • anatomy: differences in leaf hairs and fibre bundles, from unpublished work.

Other species can also be mistaken for it:

  • Zamia acuminata, of the Pacific slope of Costa Rica (San José province): smaller, with an underground or short stem, pollen sacs on the lower face of the male scales only, and downy grey-brown female cones (Lindström and colleagues, 2013); Gómez (1982) already separated it by its fewer, tail-tipped leaflets and spiny petiole;
  • Zamia gomeziana, of Costa Rica: longer leaflets with a straight lower margin and a much longer tip; in Zamia pseudomonticola the leaflets are less than seven times longer than wide, with a convex lower margin, and the greenish cones have shorter stalks (Acuña-Castillo, 2010);
  • Zamia elegantissima and Zamia stevensonii, of central Panama: petiole almost without prickles, flat leaflets without a lengthwise fold, pollen sacs on the lower face only (Taylor Blake and Holzman, 2012);
  • Zamia monticola, of Guatemala: related in name only; Gómez (1982) thought it close, but separated it by its hairless, unarmed petiole, the absence of persistent leaf bases, and its cones.

Taxonomy

Zamia pseudomonticola L.D.Gómez ex D.W.Stev. & Sabato is an accepted name according to The World List of Cycads, and GBIF gives it as accepted; POWO could not be consulted directly. Luis Diego Gómez described the species in 1982 in Phytologia (volume 50, page 402), in a paper in which he also described Zamia fairchildiana. His citation of the type gave neither collector nor number, a reference required by the Code of nomenclature; Stevenson and Sabato supplied it in 1986 in Taxon (volume 35, page 141), after seeing the holotype, which sets the date of valid publication at 1986 and explains the form “ex D.W.Stev. & Sabato” (The World List of Cycads, after Tropicos). The holotype, collected by Gómez under number 18118 according to Acuña-Castillo (2010), comes from the Cotón site, at the south-western foot of Cerro Pando, near Sabalito (Coto Brus, Puntarenas province), at 1,300 m, in mixed forest of oak (Quercus), Wimmeria and Symplocos; it is kept in the National Herbarium of Costa Rica (CR), with isotypes in the herbaria F and ND.

A disputed species

The status of the species has been debated since it was described. Schutzman, Vovides and Adams (1998) considered it the same species as Zamia fairchildiana: in their view it differed only in one leaflet character, varying continuously from one population to the next, and Gómez had cited a single specimen. The treatment of the Zamiaceae in the Manual de plantas de Costa Rica (Merello, 2003 according to The World List of Cycads, 2004 according to Acuña-Castillo) also cast doubt on it. Jay Vannini (2019) reports, after Whitelock (2002) and Calonje (2006), that searches at the type locality had failed to find plants matching the description, suggesting a mere form of Zamia fairchildiana; Acuña-Castillo (2010), on the contrary, writes that the species is locally common on the slopes of Cerro Pando.

Other authors keep it. Acuña-Castillo (2010) found, through a statistical analysis of leaf proportions, significant differences between the two species, adding to those of the cones, and cites the opinion of Gómez and of Stevenson (2007) in favour of two species. Lindström and colleagues (2013) treat it as the sister species of Zamia fairchildiana, and The World List of Cycads accepts it. In 2014, on the French forum Fous de palmiers, an experienced grower remained sceptical, suggesting that the differences in leaflets and cones might reflect growing conditions. In practice, a plant from southern Costa Rica labelled “Zamia fairchildiana” may belong to this species, especially if it comes from above 1,000 m.

Etymology and history

The epithet combines the Greek pseudo-, “false”, with the name of Zamia monticola, a cycad of Guatemala, and refers to the supposed resemblance and kinship between the two species (Haynes, 2022, followed by The World List of Cycads; Acuña-Castillo, 2010). Gómez (1982) did write that his new species was related to Zamia monticola, while separating it by several characters.

The species was described as part of a revision of the Zamia of Costa Rica and Panama, which until then had been filed in herbaria under Zamia skinneri or Zamia pseudoparasitica. Gómez expected it to occur in neighbouring parts of Panama; Acuña-Castillo (2010) reports, after Taylor (2007), that it had recently been collected there, in western Chiriquí near the border. Gómez and his colleagues studied it at the Las Cruces biological station from 1985 to 1995, but that work was never published.

Common names

No common name is attested, in English, in Spanish or in any other language; Species+ lists none.

In the wild

According to Acuña-Castillo (2010), Zamia pseudomonticola is endemic to the ranges of southern Costa Rica (the Pacific slope of the Talamanca range, in San José and Puntarenas provinces, and the southern Fila Costeña, in Puntarenas) and western Panama (Chiriquí). In Costa Rica it grows in the understorey of premontane and lower montane forest, very wet to rain forest, between 800 and 1,600 m, on moderate to steep slopes. It is locally common in the Las Cruces biological reserve and on the slopes of Cerro Pando, and scarcer further north along the Talamanca, at least to the foot of Cerro Chirripó. The World List of Cycads gives only Puntarenas province for Costa Rica.

In Panama, Taylor Blake and Holzman (2012) place it above 1,000 m in Chiriquí province, in the north-west or in the north-east of the province depending on the passage of their paper. Taylor and colleagues (2012) include it among the species of submontane evergreen forest, between 700 and 1,200 m, with more than 3,000 mm of rain a year and temperatures of 21 to 24 °C (70 to 75 °F), while citing it elsewhere as an example of a high-altitude species, above 1,500 m.

Ecology

Acuña-Castillo (2010) reports several observations. At Las Cruces, the plant collects a lot of plant debris between its leaf bases, like some rosette palms, which encourages saprophytic fungi on the top of the stem and on the petioles. Caterpillars of butterflies of the genus Eumaeus feed on its leaves and can sometimes strip a plant entirely and damage its buds and cones. Its reproductive cycle is not strictly seasonal and depends mainly on the light available in the understorey. Seedlings carry a single leaf with four leaflets, on a smooth or slightly prickly petiole.

In an unpublished experiment at Las Cruces, L.D. Gómez obtained as many seeds from cones protected from insects as from cones left open, which in his view suggests an important role for wind in pollination, although beetles (erotylids and weevils) are common in the cones; Acuña-Castillo points out that specialists now regard beetles as the main pollinators of cycads. Another study by Gómez (1993), at the Wilson garden, attributes seed dispersal, over a few tens of metres, to birds: a tanager (Ramphocelus costaricensis), a saltator (Saltator striatipectus) and a thrush (Turdus grayi). Published under the name Zamia fairchildiana, it concerns, according to Acuña-Castillo, plants of Zamia pseudomonticola, and he considers it likely that much of Gómez’s unpublished work on Zamia fairchildiana in fact refers to this species.

Conservation status and regulation

Zamia pseudomonticola is rated Least Concern (LC) on the IUCN Red List, in an assessment by J.D. Bösenberg dated 26 June 2020 and published in 2022 (category confirmed by GBIF on 25 October 2026; the Red List page itself could not be consulted). An earlier assessment, by D.W. Stevenson, was published in 2010; its category could not be checked. The species is locally common at Las Cruces and on Cerro Pando (Acuña-Castillo, 2010); no threat specific to it has been described.

Like all Zamia except Zamia restrepoi, which is in Appendix I, it falls under CITES Appendix II through the listing of the family Zamiaceae, in force since 4 February 1977 according to Species+. Annotation #4 exempts in particular seeds, pollen, seedlings and tissue cultures obtained in vitro and transported in sterile containers; international trade in the plants themselves requires a permit. In the European Union the species falls under Annex B of Regulation (EC) No 338/97, whose current annexes are set by Regulation (EU) 2026/1383, applicable since 29 June 2026; Species+ shows Annex A until February 2017. For plants from Panama, Species+ also records, since 19 June 2025, a zero export quota set by that country for wild-collected specimens (CITES Notification No. 2025/079), except for scientific, personal, medical, educational or judicial purposes.

This general information, checked on 18 October 2026, 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 seed-raised plants.

Growing Zamia pseudomonticola

No growing guide specific to Zamia pseudomonticola has been published, and the available information is indirect:

  • in Costa Rica the species is grown at the Wilson Botanical Garden, near San Vito: Acuña-Castillo (2010) publishes a photograph of a female cone from a plant in this garden; a visitor reported on the Fous de palmiers forum in 2009 many Zamia planted throughout the garden and presented as Zamia fairchildiana, an identification that Acuña-Castillo disputes for the plants of that garden;
  • in cultivation, plants without prickles on their first leaves develop them years later (Acuña-Castillo, 2010);
  • Simon Lavaud, of the French specialist nursery Cycadales.eu in Montpellier, puts the species in his group of Zamia from Central America and lowland forests, rated “difficult” outside the tropics, and advises for this group a free-draining, neutral to acid compost, about 22 °C (72 °F) at night with short spells around 15 °C (59 °F) tolerated, 28 to 30 °C (82 to 86 °F) by day and air humidity of 70 to 90 % (Lavaud, 2023). He notes that in Montpellier, even in July and August, night minimums of about 19 °C (66 °F) are borderline compared with the climates in which this group grows. This placing is surprising for a species of 800 to 1,600 m, and the group advice is not based on any trial with Zamia pseudomonticola.

Its habitat suggests a plant for shade, moist soil and very humid air, but no source has confirmed this in cultivation. The build-up of debris at the heart of the plant seen in the wild, which favours fungi, suggests keeping the top of the stem clean and well ventilated; this is a deduction, not published advice.

Outdoor and in-ground cultivation

No outdoor planting has been documented outside the species’ native range. Within it, the Wilson Botanical Garden in Costa Rica, at middle altitude in the tropics, is the only place where it is known to be grown in the ground. Elsewhere, a frost-free, constantly humid climate would be the only one in which planting out could be considered; this is a deduction from its habitat, not a tested result.

Container cultivation

No container-growing report has been published. On the information available, it is a plant for a warm, humid, shaded glasshouse, in a deep pot of free-draining compost, within the range advised by Cycadales.eu for its group.

In cultivation in the UK, US and Australia

In short: declared by one British garden, present in several American collections and in two Australian gardens.

  • United Kingdom: the Royal Botanic Gardens, Kew, declares the species to BGCI; the declaration does not say how or since when it is grown.
  • United States: the online catalogue of Montgomery Botanical Center (Coral Gables, Florida) lists four accession numbers, from 2001, 2006, 2015 and 2018 according to their numbering; BGCI also records it at the New York Botanical Garden and at the botanical garden of the University of Hawaii at Hilo (catalogue and BGCI queried on 25 October 2026).
  • Australia: Royal Botanic Garden Sydney and Cairns Botanic Gardens (Queensland), according to BGCI.

A BGCI declaration shows that a garden held the plant at some point, not that it is alive there today, and given the confusion of names, labels may read Zamia fairchildiana or Zamia pseudomonticola for similar plants.

Propagation

The species is propagated from seed, after a female plant has been pollinated by a male coning at the same time; in cultivation pollination is usually done by hand, even though Gómez’s experiment suggests a role for wind. No sowing protocol specific to the species has been published; as with other Zamia, sow fresh seed, cleaned of its fleshy coat with gloves on. Seedlings first produce a single leaf with four leaflets (Acuña-Castillo, 2010). Seeds are exempt from CITES under annotation #4, but they must come from cultivated plants of legal origin; given the confusion of names, the identity of seed sold under this name deserves checking.

Pests and diseases

In the wild, Eumaeus caterpillars can strip a plant entirely, and saprophytic fungi grow on the debris collected on top of the stem and on the petioles (Acuña-Castillo, 2010). No disease specific to the species has been documented in cultivation. In general, Zamia are most at risk from root and stem rot in cold, sodden compost, and from scale insects. Among these, Aulacaspis yasumatsui, the Asian cycad scale, which can kill an adult Cycas within months, includes the genus Zamia among its hosts according to the EPPO database, after Marler, Lindström and Watson (2021); no attack has been reported on Zamia pseudomonticola itself.

Cold hardiness

There are no data on the cold tolerance of Zamia pseudomonticola, either in the wild or in cultivation. It is a tropical species of middle altitudes: the only published climatic indication is the range of 21 to 24 °C (70 to 75 °F) given by Taylor and colleagues (2012) for the submontane forests of Panama in which they place it. This gives no clue to a survival limit, and nothing shows that the altitude of its range gives it any frost tolerance.

Mediterranean and European experience

No in-ground or container cultivation has been reported in France or Italy, and no dated frost episode concerns the species. The messages on the Fous de palmiers forum that mention it (2012 to 2014) deal with its validity and give no growing data. At the Jardin zoologique tropical in La Londe-les-Maures (Var, on the French Riviera), no observation of this species has been published. For readers in Mediterranean-type climates such as California or southern Australia, a heated glasshouse or conservatory remains the only prudent option.

United Kingdom, United States and Australia

No cold record has been published, on forums or by botanic gardens. Trebrown, a British nursery, gives it USDA zone 9b, a commercial rating, not a measured result. In the UK it needs a heated, humid glasshouse.

Toxicity and precautions

No toxicity study specific to Zamia pseudomonticola has been published. The risk is, however, documented in the genus and in other cycads: pharmacological studies cited by The Gymnosperm Database found in Zamia 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 of Zamia pseudomonticola is documented.

Frequently asked questions

Is Zamia pseudomonticola a real species?

Yes for The World List of Cycads, which accepts it, but the debate is not closed. Several authors have placed it in Zamia fairchildiana; others, including Acuña-Castillo (2010) and Lindström and colleagues (2013), keep it apart on the basis of its cones and leaf proportions.

How can it be told from Zamia fairchildiana?

Mainly by the cones and the altitude. Zamia pseudomonticola has male cones under 14 cm long and greenish female cones on a stalk shorter than 5 cm, and lives mostly above 1,000 m; Zamia fairchildiana, a lowland plant, has larger cones, greyish female scales and leaflets finely toothed near the tip.

Is its petiole prickly?

It depends on the plant. The original description spoke of a petiole without prickles, but that was true of the single type specimen; Acuña-Castillo (2010) describes it as smooth or prickly, and Taylor Blake and Holzman (2012) as prickly up to the base of the rachis in Panama. Cultivated plants acquire prickles with age.

Where does its name come from?

From the Greek pseudo-, “false”, and Zamia monticola, a Guatemalan cycad to which Gómez thought it related. The name therefore means “false monticola”.

Is it endangered?

No, according to the IUCN, which rates it Least Concern (2022). It is locally common in some mountain forests of southern Costa Rica, such as the Las Cruces biological reserve.

Can I grow it in the UK?

Only under heated glass, and without published guidance. Its cold tolerance is unknown; it comes from tropical forests at middle altitude, has never been tested in cold conditions, and planting out is not an option anywhere in Britain.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Gómez P., L.D. (1982). Plantae mesoamericanae novae. II. Phytologia 50(6): 401–404. [Original description, not validly published for lack of a reference to the collector of the type; full text read.]
  • Stevenson, D.W. & Sabato, S. (1986). Typification of names in Zamia L. and Aulacophyllum Regel (Zamiaceae). Taxon 35(1): 134–144. https://doi.org/10.2307/1221051 [Valid publication of the name (p. 141); not consulted, explanation taken from The World List of Cycads.]
  • Acuña-Castillo, R.H. (2010). Revisión taxonómica y morfológica y distribución de Zamia (Zamiaceae) en Costa Rica. Master’s thesis, Universidad de Costa Rica, San José. hdl:10669/84075 [Revision not published in a journal; full text read.]
  • Lindström, A.J., Calonje, M., Stevenson, D., Husby, C. & Taylor, A. (2013). Clarification of Zamia acuminata and a new Zamia species from Coclé Province, Panama. Phytotaxa 98(2): 27–42. https://doi.org/10.11646/phytotaxa.98.2.1 [Comparison of the Zamia of the Pacific slope of Costa Rica; full text read.]
  • Taylor Blake, A.S. & Holzman, G. (2012). A new Zamia species from the Panama Canal area. The Botanical Review 78(4): 335–344. https://doi.org/10.1007/s12229-012-9105-4 [Range in Panama and key; full text read.]
  • Taylor B., A.S., Haynes, J.L., Stevenson, D.W., Holzman, G. & Mendieta, J. (2012). Biogeographic insights in Central American cycad biology. In: Stevens, L. (ed.), Global Advances in Biogeography, pp. 73–98. InTech. https://doi.org/10.5772/32253 [Range and habitats of the Zamia of Panama; full text read.]
  • Schutzman, B., Vovides, A.P. & Adams, R.S. (1998). A new Zamia (Zamiaceae, Cycadales) from central Panama. Phytologia 85(3): 137–145. [Synonymy with Zamia fairchildiana; full text read.]
  • Gómez, L.D. (1993). Birds as short-range seed dispersers of Zamia fairchildiana in SW Costa Rica. Revista de Biología Tropical 41: 905–906. [Referred to Zamia pseudomonticola by Acuña-Castillo (2010); not consulted.]
  • Merello, M. (2003). Zamiaceae. In: Hammel, B.E., Grayum, M.H., Herrera, C. & Zamora, N. (eds), Manual de plantas de Costa Rica, vol. 2. Monographs in Systematic Botany from the Missouri Botanical Garden 92: 14–16. [Reference given by The World List of Cycads (dated 2004 by Acuña-Castillo); not consulted.]
  • Bösenberg, J.D. (2022). Zamia pseudomonticola. The IUCN Red List of Threatened Species 2022: e.T42176A69840415. https://doi.org/10.2305/IUCN.UK.2022-1.RLTS.T42176A69840415.en [Current assessment, LC, dated 26 June 2020; reference checked on Crossref, category on GBIF; the Red List page could not be consulted.]
  • Stevenson, D.W. (2010). Zamia pseudomonticola. The IUCN Red List of Threatened Species 2010: e.T42176A10649173. https://doi.org/10.2305/IUCN.UK.2010-3.RLTS.T42176A10649173.en [Earlier assessment; reference checked on Crossref, category not checked.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. https://doi.org/10.11646/phytotaxa.550.1.1 [Etymology followed by The World List of Cycads; not consulted directly.]
  • Vannini, J. (2019). Central American and Panamanian cycads in field and greenhouse. Exotica Esoterica, 17 February 2019. [Online article by a naturalist and collector; read.]
  • Lavaud, S. (2023). Comment cultiver les Zamia en climat tempéré. Cycadales.eu. [Growing advice for groups of species; read directly.]
  • Marler, T.E., Lindström, A.J. & Watson, G.W. (2021). Aulacaspis yasumatsui delivers a blow to international cycad horticulture. Horticulturae 7(6): 147. https://doi.org/10.3390/horticulturae7060147 [Host plants cited after EPPO; full text 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.]