Zamia erosa

Zamia erosa is a small cycad of the Greater Antilles, found in Puerto Rico, Cuba and Jamaica, where it grows mainly on wooded limestone hills. This species of the genus Zamia was described in 1903 by Orator F. Cook and Guy N. Collins, but for many years it circulated in collections and catalogues as Zamia amblyphyllidia, a name published in 1987: in 2010 a study showed that both names apply to the same plant and that the older one takes priority. It belongs to the Zamia pumila complex of the West Indies and Florida, and the IUCN rates it Vulnerable.

Key facts about Zamia erosa

  • Accepted name: Zamia erosa O.F.Cook & G.N.Collins (1903), accepted by The World List of Cycads (version 2026.08.15) and by GBIF; POWO could not be consulted directly
  • Former names and synonyms: Zamia amblyphyllidia D.W.Stev. (1987), a synonym since 2010 and still common in the trade; in Cuba the plant has also been wrongly called “Zamia media” and “Zamia debilis”
  • Family: Zamiaceae, order Cycadales; Zamia pumila complex
  • Common names: no English name attested; “marunguay” in Puerto Rico (original description), “yuquilla de ratón” in Cuba (a name shared with other Zamia)
  • Natural range: Puerto Rico (north coast), Cuba (west, centre and east), Jamaica
  • IUCN status: Vulnerable (VU), criterion C1, assessment published in 2022
  • 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 measured data; specialist nurseries place it among the Caribbean Zamia that tolerate temperatures around freezing (see Cold hardiness)
  • Light and soil: in the wild, crevices of wooded limestone hills, edges of semi-deciduous forest on karst soils, and pine woods; in cultivation, a free-draining mineral compost, slightly to strongly alkaline
  • Habit and adult size: underground stem 4 to 10 cm across; a few leaves about 70 cm long (up to 1.5 m); leaflets 2 to 3.7 cm wide (Flora de la República de Cuba)
  • In the UK, US and Australia: listed by Montgomery Botanical Center and Fairchild Tropical Botanic Garden (Florida) and declared to BGCI by some twenty American gardens; listed by the Royal Botanic Garden Sydney and declared by Cairns and Adelaide; no British record
  • Toxicity: no data specific to the species; treat it as poisonous, like all cycads (see Toxicity and precautions)

How to recognise Zamia erosa

The leaflets are the first clue: broad, with a rounded or blunt tip, and edged in their upper part with irregular teeth that give them a gnawed look. The two names of the species describe exactly these two features: erosa refers to the margin, amblyphyllidia to the blunt tip.

The original description by Cook and Collins (1903) is very short: a plant with only one or two leaves, widely spaced leaflets that are broad and erose-toothed at the top, and a large fleshy root hidden in crevices of jagged limestone rock. The fullest description is the one in the Flora de la República de Cuba (González Géigel, 2003), which treats the species under the name Zamia amblyphyllidia, based on Cuban plants.

Stem and leaves

  • Stem: underground, 4 to 10 cm across, rarely branched.
  • Leaves: usually 4 or 5 (sometimes only 2, occasionally up to 10), about 70 cm long, exceptionally 1.5 m, hairless when mature; young leaves carry a dark reddish-brown down. The petiole, 30 to 40 cm long (up to 70 cm), has no prickles.
  • Leaflets: usually 10 to 14 pairs (from 6 to as many as 20), narrowly obovate, 7.5 to 21 cm long and 2 to 3.7 cm wide, thin to slightly leathery, with a blunt, rounded or obliquely truncate tip; the slightly thickened, faintly rolled margin carries many well-marked teeth in the upper third. The upper surface is glossy, green to yellowish green.

Cones

  • Male cones: 1 to 5, sometimes up to 8, cylindrical, 4 to 8 cm long and about 1.4 cm across, with a pointed tip, on a stalk 4 to 8 cm long; scales covered in a thick brown down.
  • Female cones: ovoid, 6 to 10 cm long and 2 to 3 cm across, ending in a conical point about 8 mm long, on a stalk about 5 cm long.

The same flora stresses that the species is very variable: leaf size and leaflet shape change according to whether the plant grows in shade or in sun, and young plants, with much smaller leaves, have been mistaken for another species. In Puerto Rico, a study of the leaflets of three populations (Newell, 1986) found broader leaflets, and more of them per leaf, at Arecibo, on the north coast, than in the two other populations studied.

Growers describe the plant in much the same terms. Jungle Music, a cycad nursery in San Diego, California, describes its “Zamia amblyphyllidia” as a dwarf species with a caudex about 15 cm (6 in) across, arching leaves about 90 cm (3 ft) long, small leaflets and unarmed petioles, and adds that it suckers to form clumps. That last point sits oddly with the Cuban flora (stem rarely branched) and with the Puerto Rican population study described under In the wild, where only 7 per cent of plants were branched; cultivated plants may behave differently, but no source explains the difference.

Hybrids

No hybrid has been described. In Puerto Rico, a genetic study using 31 microsatellite markers and ten populations (Meerow and colleagues, 2012) found mixing only between Zamia portoricensis and Zamia pumila, not with Zamia erosa, whose populations are on the contrary more than three times as differentiated from one another as those of the two other species.

Possible confusion

The Zamia of the West Indies look very much alike and were long lumped into a single species. In Puerto Rico, three species share the island (Meerow and colleagues, 2012) and differ above all in leaflet width (Newell, 1986):

  • Zamia erosa, on the north coast, with broad, blunt leaflets;
  • Zamia pumila, in the south of the island and also in Hispaniola and Cuba; the Flora de la República de Cuba gives it fewer than 10 pairs of leaflets and larger cones (male cones 6 to 11 cm, female cones 8 to 14 cm);
  • Zamia portoricensis, also in the south, notably around Guánica and in the Susúa forest, with long, narrow leaflets.

In Cuba, the key in the same flora separates Zamia amblyphyllidia (now Zamia erosa) from the other species of the island by the combination of more than 10 pairs of leaflets, leaflets more than 2 cm wide and small ovoid female cones; Zamia pygmaea, Zamia stricta and Zamia integrifolia have much narrower leaflets. Simon Lavaud, of the French specialist nursery Cycadales.eu, points out that the Cuban Zamia are still poorly delimited and that growers recognise “types” rather than clear-cut species there; he illustrates an “erosa type” beside an “integrifolia type” and a “pygmaea type” (Lavaud, 2023). Finally, the 1899 photographs that now serve as the type of Zamia erosa were labelled “Zamia integrifolia”: provenance remains the safest clue, and many plants still circulate under the name amblyphyllidia.

Taxonomy

Zamia erosa is an accepted name according to The World List of Cycads and GBIF; POWO could not be consulted directly. Its history is one of the most tangled among the American cycads. In 1903, Cook and Collins described the species in their inventory of the economic plants of Puerto Rico (Contributions from the U.S. National Herbarium 8(2): 267), from a plant found in the forests of the limestone hills south of Vega Baja, without citing a herbarium specimen.

From Zamia amblyphyllidia back to Zamia erosa

In 1980, James Eckenwalder merged all the Zamia of the West Indies and Florida into a very broadly defined Zamia pumila and designated a “lectotype” for Zamia erosa. In 1987, Dennis W. Stevenson described Zamia amblyphyllidia (Fairchild Tropical Garden Bulletin 42(3): 26), from a type collected on 30 January 1985 in the Río Abajo forest at Utuado, Puerto Rico, and kept in the herbarium of the New York Botanical Garden (according to the Flora de la República de Cuba).

In 2010, Michael Calonje, Alan W. Meerow and Dennis W. Stevenson settled the question in the journal Taxon (59(2): 637–642). According to the abstract, Eckenwalder’s designation could not be a lectotype, because it was not based on original material of Cook and Collins, and had to be corrected to a neotype; as that neotype seriously conflicted with the original description, in the light of descriptive and geographical clues overlooked until then and of new collections made near the type locality, it was replaced. The new neotype is an archival photographic record kept at the United States National Herbarium (sheet NA no. 88468, negative no. 2376), taken at Vega Baja in 1899 (The World List of Cycads). The authors concluded that Zamia erosa is the earliest validly published name for the species until then called Zamia amblyphyllidia: the 1903 name has priority. It is one of the rare cases in which the author of a name co-signs the paper that sinks it into synonymy. For the reader, the practical consequence is simple: a plant sold as Zamia amblyphyllidia is Zamia erosa.

Place in the genus

Molecular studies place the species in the Zamia pumila complex, the group of the Zamia of the West Indies and Florida (Calonje and colleagues, 2019, according to The World List of Cycads). The transcriptome phylogeny of Lindstrom and colleagues (2024), which included a sample of Zamia erosa from Puerto Rico, recovered this Caribbean clade (their clade I, the West Indian species together with Zamia integrifolia of Florida) as a strongly supported group, sister in most of their analyses to the small Fischeri clade of eastern Mexico; they date the diversification within the Caribbean clade to the late Miocene, around 8 million years ago. In Puerto Rico, according to the abstract of Meerow and colleagues (2012), the populations of Zamia erosa may derive from an independent colonisation of the island.

Etymology and history

The epithet comes from the Latin erosus, “irregularly notched, toothed”, and refers to the toothed margin of the leaflets (Haynes, 2022, as given by The World List of Cycads). The synonym amblyphyllidia refers to their blunt tip: the two names describe two features of the same leaflet.

Orator F. Cook, the botanist in charge of tropical agricultural research at the United States Department of Agriculture, and his assistant Guy N. Collins found the plant during two journeys to Puerto Rico, in 1899 and 1901, devoted to an inventory of the island’s useful plants. They noted that local people dug up its large fleshy root to extract starch. The photographs taken at Vega Baja in 1899 now serve as the type.

Common names

No English name is attested. In Puerto Rico, Cook and Collins (1903) give the name “marunguay” for this species, which they also apply to Zamia portoricensis; the form “marunguey” or “marungüey”, of Indigenous origin, refers to the island’s Zamia in general and survives in several place names (Pagán-Jiménez and Lazcano-Lara, 2013). In Cuba, the Flora de la República de Cuba gives “yuquilla de ratón” (after Roig, 1963), a name it also cites for other Zamia of the island, so it is not specific to this species. In the trade, the plant is still often labelled Zamia amblyphyllidia.

In the wild

The World List of Cycads records the species in Cuba, Jamaica and Puerto Rico; the Dominican Republic, sometimes cited, does not appear in that list. In Puerto Rico, it occupies the north coast (Meerow and colleagues, 2012); the type locality lies in the forests of the limestone hills south of Vega Baja, and the best-studied population is that of the Cambalache forest, near Arecibo, in the karst region of the north of the island. In Cuba, the Flora de la República de Cuba records it from the west (Pinar del Río, La Habana, Matanzas, Isla de la Juventud) to the centre (Cienfuegos, Sancti Spíritus, Villa Clara) and the east (Holguín, Guantánamo), at the edge of semi-deciduous forest on karst soils and in pine woods on schist. For Jamaica, the published sources do not describe the habitat.

Life cycle

The Cambalache plants, then published under the name Zamia debilis, were followed for 29 months by Negrón-Ortiz and Breckon (1989). According to the abstract of their study, it is an understorey plant; more than half of the individuals have a single stem and one or two leaves, and only 7 per cent are branched. Leaves appear all year round, with a peak at the start of the rainy season, in May or June, and a low during the dry months, from February to April; they live on average 2.3 years and die by shedding their leaflets one by one.

A second study by the same team (Negrón-Ortiz, Gorchov and Breckon, 1996) followed germination, according to a bibliographic summary: the root emerges first, then the first leaf, one to seven months later. Seeds released early, before the dry season, germinate faster but die more often during their first dry season; after three years, survival of the two cohorts is similar, around 2 to 3 per cent. Plants with ten leaflets or fewer hardly ever produce cones.

Pollination and genetics

The beetle Pharaxonotha portophylla, described in 2008 by Franz and Skelley, was collected in the cones of Zamia amblyphyllidia (now Zamia erosa) at Cambalache and in those of Zamia portoricensis in the Susúa forest; the authors present it as a pollinator of the Puerto Rican Zamia. According to the abstract of Meerow and colleagues (2012), a small population of Zamia erosa living in a saline environment appears to be under marked selection.

Conservation status and regulation

Zamia erosa is rated Vulnerable (VU) on the IUCN Red List, under criterion C1 (a small population in decline), in the assessment by J.D. Bösenberg and D.W. Stevenson published in 2022 (The World List of Cycads; GBIF gives the same category; the Red List itself could not be consulted). The IUCN cycad action plan (Donaldson, 2003) already gave it this status under the name Zamia amblyphyllidia, estimating the total population at 2,000 to 3,000 plants, in moderate decline because of habitat destruction, with populations present in protected areas.

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

Zamia erosa belongs to the easiest group of the genus. Simon Lavaud of Cycadales.eu places the Zamia of Florida and the Caribbean, Zamia erosa among them, in his “easy” group: they tolerate temperatures around freezing, cope well with Mediterranean-type winters, withstand drought, because their habitats have dry seasons that are sometimes very marked, and nearly all come from limestone soils, like those of southern Europe (Lavaud, 2023). For this group he recommends:

  • a free-draining compost, slightly to strongly alkaline, made of about 80 per cent mineral material; these species do not like acid conditions;
  • any kind of water, including hard water;
  • in winter, 1 to 10 °C (33.8 to 50 °F), with daytime rises to 15 to 20 °C (59 to 68 °F); prolonged cool spells are tolerated if the compost is kept fairly dry without drying out completely;
  • in summer, 15 to 20 °C (59 to 68 °F) at night and 25 to 30 °C (77 to 86 °F) by day, up to 40 °C (104 °F) with generous watering; at least four to six months of summer temperatures a year are essential.

These are recommendations from experience for the whole Caribbean group, not measurements made on Zamia erosa alone. Jungle Music adds that its plants like filtered light and prefer partial sun or strong filtered light, but can be grown in sun along the coast of southern California.

Outdoor and in-ground cultivation

In-ground growing is documented only in frost-free or nearly frost-free climates. In the United States the species is held by several gardens in southern Florida and coastal California (see the next section), and its cultivation in central Florida is the subject of a short note in The Cycad Newsletter (Broome, 2009). In the wild it lives in rock crevices and on well-drained karst, which explains the emphasis that growers put on drainage.

Container cultivation

Its small size and underground stem make it a good pot plant. A mineral, free-draining, slightly alkaline compost, a bright position out of the hottest sun and a drier, cool but frost-free winter follow the advice above. In cool climates such as the UK, keep it in a frost-free glasshouse or conservatory in winter and give it as much summer warmth as possible.

In cultivation in the UK, US and Australia

In short: widely held in American gardens, present in three Australian gardens, no British record.

  • United States: Montgomery Botanical Center (Coral Gables, Florida) lists 23 accession numbers under Zamia erosa in its online catalogue, 18 from 2003, four from 2008 and one from 2014, plus a plant recorded as Zamia aff. amblyphyllidia (2016). Fairchild Tropical Botanic Garden (Coral Gables) lists it in its online catalogue (Garden Explorer, updated on 16 October 2026). BGCI also records it, under Zamia erosa or Zamia amblyphyllidia, at Marie Selby Botanical Gardens and Naples Botanical Garden in Florida, the Huntington, Ganna Walska Lotusland, San Diego Botanic Garden, the San Diego Zoo, Descanso Gardens and the University of California Botanical Garden at Berkeley in California, the University of Hawaii at Hilo and the National Tropical Botanical Garden in Hawaii, the United States Botanic Garden in Washington, the New York Botanical Garden, Denver Botanic Gardens, and the Mercer Arboretum and the John Fairey Garden in Texas (queried on 25 October 2026).
  • Australia: the Royal Botanic Garden Sydney lists it in its online catalogue (Garden Explorer, updated on 1 October 2026); Cairns Botanic Gardens (Queensland) and the Botanic Garden of Adelaide declare it to BGCI.
  • United Kingdom: no record in BGCI or in the online catalogues of British gardens (Edinburgh, Cambridge, Chelsea Physic Garden).

Outside these countries, BGCI lists gardens in Frankfurt, Prague, Alcalá de Henares (Spain), Singapore and Shenzhen (China). A BGCI declaration shows that a garden held the plant at some point, not that it is alive today, and the sources do not say whether these plants are grown outdoors or under glass.

Propagation

The species is grown from seed; it has separate male and female plants, and pollination must be done by hand where the pollinating beetles are absent. In the wild, germination happens in two stages, the first leaf appearing only one to seven months after the root (Negrón-Ortiz and colleagues, 1996): be patient before judging a sowing. Seeds are exempt from CITES under annotation #4, which makes exchanges easier: in 2009 and 2010, French growers on the Fous de palmiers forum were offering seed and seedlings of “Zamia amblyphyllidia”. Seeds must still come from plants of legal origin.

Pests and diseases

No pest or disease specific to the species has been documented in the wild. In cultivation, Jungle Music illustrates a mealybug infestation on a “Zamia amblyphyllidia”: these insects hide in tight spots and on the undersides of the leaves. For the Caribbean Zamia, Lavaud (2023) names root rot in a compost that stays too wet in cool weather as the main risk, to be prevented by a mineral compost and a rather dry winter.

Cold hardiness

No measured cold tolerance exists for Zamia erosa. The species belongs to the most tolerant group of the genus, and the specialist sources agree on temperatures around freezing, without dated observations. Jungle Music states that its plants tolerate temperatures “into the upper twenties F”, that is around −2 °C (28 °F); Lavaud (2023) speaks only of temperatures “close to zero” for the Caribbean species other than Zamia integrifolia. These are nursery assessments, not measured limits.

Mediterranean and European experience

No in-ground result has been published in France or elsewhere in Europe, and no dated frost episode concerns the species; the French forum messages about it (2009–2010) concern seed exchanges and seedlings, without cold data. A comparison is nevertheless useful for readers in climates such as California, southern Australia or the mildest parts of southern England, provided it is not transferred as it stands: at the Jardin zoologique tropical in La Londe-les-Maures, on the Var coast of southern France, a plant of Zamia integrifolia, the hardiest member of the complex, survived −7 °C (19.4 °F) in February 2012, with damage to the foliage. For this Florida species, Lavaud (2023) reports leaf damage from −5 °C (23 °F) but possible survival, leafless, at much lower temperatures. Nothing shows that Zamia erosa would do as well: until trials are published, grow it in a pot and overwinter it frost-free.

United Kingdom, United States and Australia

No dated cold record has been published. Trebrown, a British specialist nursery, gives a cold hardiness zone of 9b in its catalogue under Zamia erosa and 10a under Zamia amblyphyllidia, without stating the basis of these commercial ratings: the two entries concern the same species, which shows how approximate they are. In the UK it is a plant for a frost-free glasshouse; in Florida, coastal California and the warmer parts of Australia, it is grown outdoors by botanical gardens, without published records of the minimum temperatures they experience.

Toxicity and precautions

No toxicity study specific to Zamia erosa 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. The traditional extraction of starch from the root involved long preparation to remove the toxins and must not be imitated. 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

Cook and Collins (1903) report that people around Vega Baja dug up the large fleshy root of this species to make starch. More broadly, Zamia are described as one of the main food plants of the inhabitants of Hispaniola and Puerto Rico, before and after the arrival of Europeans (Pagán-Jiménez and Lazcano-Lara, 2013); in Cuba, the Flora de la República de Cuba mentions, for other species, the use of the starch to stiffen linen.

Frequently asked questions

Are Zamia erosa and Zamia amblyphyllidia the same plant?

Yes. In 2010, Calonje, Meerow and Stevenson showed that they are the same species; the older name, Zamia erosa (1903), takes priority. Zamia amblyphyllidia (1987) is now a synonym, although it is still widely used in the trade.

What do the two names mean?

Erosa means “irregularly toothed”, for the margin of the leaflets; amblyphyllidia means “with blunt leaflets”, for their rounded tip.

Where does it grow?

In Puerto Rico, on the north coast, in Cuba and in Jamaica, mostly on limestone. The best-studied population is that of the Cambalache forest, near Arecibo.

Is it endangered?

Yes, moderately: the IUCN rates it Vulnerable, and in 2003 its total population was estimated at 2,000 to 3,000 plants.

How can it be told from Zamia pumila?

By its leaflets and cones: Zamia erosa usually has more than 10 pairs of leaflets more than 2 cm wide and small cones, Zamia pumila fewer than 10 pairs and larger cones. In Puerto Rico, the range also helps: erosa in the north, pumila in the south.

Is it easy to grow?

Yes, according to specialist nurseries: like the other Caribbean Zamia, it wants a mineral, alkaline compost, tolerates hard water, drought and cool winters, provided it stays rather dry.

Can it be grown outdoors in the UK?

No, not on present evidence. No measured frost tolerance exists, and nurseries speak only of temperatures around freezing; in the UK, keep it in a pot in a frost-free glasshouse or conservatory in winter.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Cook, O.F. & Collins, G.N. (1903). Economic plants of Porto Rico. Contributions from the United States National Herbarium 8(2): 57–269 (Zamia erosa: 267). [Original description; read on the Internet Archive.]
  • Eckenwalder, J.E. (1980). Taxonomy of the West Indian cycads. Journal of the Arnold Arboretum 61: 701–722. https://doi.org/10.5962/bhl.part.8542 [Revision merging the West Indian Zamia; reference checked on Crossref, text not consulted.]
  • Stevenson, D.W. (1987). Again the West Indian zamias. Fairchild Tropical Garden Bulletin 42(3): 23–27. [Description of Zamia amblyphyllidia; not consulted.]
  • Calonje, M., Meerow, A.W. & Stevenson, D.W. (2010). The typification of Zamia erosa and the priority of that name over Zamia amblyphyllidia. Taxon 59(2): 637–642. https://doi.org/10.1002/tax.592031 [Abstract read; neotype details from The World List of Cycads.]
  • González Géigel, L. (2003). Zamiaceae. In: Greuter, W. (ed.), Flora de la República de Cuba, series A, fascicle 8(4). A.R. Gantner, Ruggell; online edition, Botanischer Garten Berlin, 2024. https://doi.org/10.3372/frc.8.4 [Description of the species under the name Zamia amblyphyllidia; read directly.]
  • Newell, S.J. (1986). Variation in leaflet morphology among three populations of Zamia L. in Puerto Rico. Taxon 35(2): 234–242. https://doi.org/10.2307/1221265 [Abstract read.]
  • Negrón-Ortiz, V. & Breckon, G.J. (1989). Population structure in Zamia debilis (Zamiaceae). I. Size classes, leaf phenology, and leaf turnover. American Journal of Botany 76(6): 891–900. https://doi.org/10.1002/j.1537-2197.1989.tb15067.x [Cambalache population; abstract read.]
  • Negrón-Ortiz, V., Gorchov, D.L. & Breckon, G.J. (1996). Population structure in Zamia (Zamiaceae) in northern Puerto Rico. II. Seed germination and stage-structured population projection. International Journal of Plant Sciences 157(5): 605–614. https://doi.org/10.1086/297381 [Known from a bibliographic summary; text not consulted.]
  • Franz, N.M. & Skelley, P.E. (2008). Pharaxonotha portophylla (Coleoptera: Erotylidae), new species and pollinator of Zamia (Zamiaceae) in Puerto Rico. Caribbean Journal of Science 44(3): 321–333. https://doi.org/10.18475/cjos.v44i3.a7 [Known from the abstract of a paper by the same authors; full text not consulted.]
  • Meerow, A.W., Francisco-Ortega, J., Calonje, M., Griffith, M.P., Ayala-Silva, T., Stevenson, D.W. & Nakamura, K. (2012). Zamia (Cycadales: Zamiaceae) on Puerto Rico: asymmetric genetic differentiation and the hypothesis of multiple introductions. American Journal of Botany 99(11): 1828–1839. https://doi.org/10.3732/ajb.1200494 [Abstract read.]
  • 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 [Places the species in the Zamia pumila complex; cited after The World List of Cycads.]
  • 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 Puerto Rico; Caribbean clade (clade I) and its relationship to the Fischeri clade; full text consulted.]
  • Pagán-Jiménez, J.R. & Lazcano-Lara, J.C. (2013). Toponymic data helps to reveal the occurrence of previously unknown populations of wild Zamia pumila L. on volcanic substrates in south central Puerto Rico. Ethnobiology Letters 4: 52–58. https://doi.org/10.14237/ebl.4.2013.9 [Abstract read; concerns Zamia pumila and the Indigenous name of the genus, not Zamia erosa itself.]
  • Donaldson, J.S. (ed.) (2003). Cycads. Status Survey and Conservation Action Plan. IUCN/SSC Cycad Specialist Group, Gland and Cambridge. [Table 6.1: Zamia amblyphyllidia, VU C1, 2,000 to 3,000 plants; read directly.]
  • Bösenberg, J.D. & Stevenson, D.W. (2022). Zamia erosa. The IUCN Red List of Threatened Species 2022: e.T187835A69874722. [Current assessment (VU); cited by The World List of Cycads, Red List page not consulted.]
  • Broome, T. (2009). Growing Zamia erosa and Zamia pumila in central Florida. The Cycad Newsletter 32(2): 5–6. [Cited by The World List of Cycads; not consulted.]
  • Lavaud, S. (2023). Comment cultiver les Zamia en climat tempéré. Cycadales.eu. [Growing advice for groups of species; read 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.]
  • 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.]