Zamia hamannii

Zamia hamannii is a cycad of the Caribbean coast of western Panama, in the Bocas del Toro region, where it grows in forest on coastal slopes and down to the beaches, sometimes in reach of seawater. This species of the genus Zamia, described in 2008, belongs to the Zamia skinneri group of large Central American Zamia with broad, pleated leaflets, and stands out for its pink to orange-pink new leaves covered in silvery down. Panama’s environment ministry regards it as endemic to the island of Escudo de Veraguas. The IUCN rates it Vulnerable, and illegally collected plants were seized there in 2022.

Key facts about Zamia hamannii

  • Accepted name: Zamia hamannii A.S.Taylor, J.L.Haynes & Holzman (2008), 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; its populations were previously referred to Zamia skinneri
  • Family: Zamiaceae, order Cycadales
  • Common names: no name attested, in English or in any other language
  • Natural range: Panama, Bocas del Toro region; the island of Escudo de Veraguas according to Panama’s environment ministry (2022), the Valiente Peninsula and nearby offshore islets according to Vannini (2019)
  • IUCN status: Vulnerable (VU D1+2), 2022 assessment; Critically Endangered proposed by its authors in 2008
  • 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; young plants came through the winter of 2014–2015 in the ground, in shade, on the Mediterranean coast west of Marseille, where the nearest weather station recorded −3.0 °C (26.6 °F); plants in the ground in Greece lose their leaves in winter at minimums of −2 to −2.5 °C (28.4 to 27.5 °F), according to a second-hand report (see Cold hardiness)
  • Light and soil: in the wild, humid tropical forest on coastal slopes (acid humus over mudstone) and calcareous beach sand, sometimes reached by the sea; partial shade in cultivation according to growers
  • Habit and adult size: trunk up to 2.4 m tall and 7.5 to 20 cm across, sometimes branched; up to 27 leaves 1.06 to 2.27 m long, with 5 to 10 pairs of leaflets (middle leaflets 26 to 62 cm by 7 to 13 cm)
  • In the UK, US and Australia: Montgomery Botanical Center (five accession numbers from 2004), San Diego Botanic Garden and two Hawaiian gardens (BGCI); Royal Botanic Garden Sydney; 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 hamannii

Zamia hamannii is a large, trunk-forming Zamia of the Zamia skinneri group, the Central American Zamia with broad, pleated leaflets; its pinkish brown or pink new leaves, covered in silvery down, set it apart. In 2022 a botanist of Panama’s environment ministry described it as a terrestrial plant, very attractive and of large size. The measurements below come from the original description (Taylor, Haynes and Holzman, 2008):

  • Trunk: up to 2.4 m tall (commonly 2 m) and 7.5 to 20 cm in diameter, solitary, sometimes branching near the base or the top after an injury.
  • Leaves: 1.06 to 2.27 m long, up to 27 per crown (12 on average), with 5 to 10 pairs of leaflets (8 on average); they emerge pinkish brown or pink, covered in silvery down, take on an orange-pink tint as they expand, then turn glossy dark green; petiole 48 to 110.5 cm long, dark green, almost black.
  • Leaflets: elliptic to oblong-elliptic, wedge-shaped at the base, acuminate, pleated between the veins, with a regularly toothed margin in the upper third; apical leaflets 23 to 51 cm by 4 to 14 cm, middle leaflets 26 to 62 cm by 7 to 13 cm, basal leaflets 35 to 49 cm by 5.5 to 13 cm.
  • Male cones: single or in groups of 2 to 6, conical-cylindrical, 9 to 12 cm by 1.5 to 2 cm, with yellowish to yellowish brown down; stalk 2.1 to 5 cm.
  • Female cones: solitary, cylindrical-globose, 11 to 28 cm by 7 to 9 cm, at first with yellow-brown to tawny down, then green or greyish green, erect or barely nodding when ripe; stalk 5 to 6.5 cm.
  • Seeds: ovoid to globose, 2.4 to 2.8 cm by 1.4 to 1.8 cm, up to 300 per cone, with a bright red fleshy coat (sarcotesta).
  • Seedlings: first leaves with four fairly narrow, acuminate leaflets.

According to its authors, Zamia hamannii differs from Zamia skinneri in its longer leaflets, its pink to orange-pink, densely silvery young leaves (bright green and hairless in Zamia skinneri) and its much more globose seeds.

In this group, the colour of the new leaves is a useful marker. According to the 2008 paper, the name Zamia skinneri applies to the plants with green new leaves on the coast of Bocas del Toro. Jay Vannini, a naturalist who grows Central American cycads, writes that all the Zamia hamannii he has seen reliably produce attractive new leaves, from brassy yellow to pale orange and peach, unlike many Zamia imperialis (Vannini, 2019). A French grower who collected its seeds on the island in 2012 reported on the Fous de palmiers forum that the seedlings have streaked green-brown leaflets, and placed the species, like Zamia imperialis, among the Zamia whose new leaf emerges brown, whereas that of Zamia skinneri always emerges green.

Hybrids

No hybrid has been demonstrated. The same French grower suggested in 2014 and 2015, on the Fous de palmiers forum, that hybrid populations might exist between Zamia skinneri and Zamia hamannii, or between Zamia hamannii and Zamia imperialis on the mainland; this is an amateur’s hypothesis, not a published finding.

Possible confusion

  • Zamia skinneri, of the mainland coast of Bocas del Toro, from which the species was separated in 2008: green new leaves;
  • Zamia imperialis, of central Panama, described in the same paper: red to brown new leaves, like Zamia hamannii, but, according to Vannini (2019), faster-growing and with less reliable new-leaf colour;
  • Zamia nesophila, another species of the Bocas del Toro archipelago described in the same paper, which grows mainly in calcareous beach sand: according to the French grower quoted above, its seedlings have very pale green leaflets;
  • Zamia neurophyllidia, with narrower, prominently veined leaflets, widespread in Central America.

Seeds of a closely related mainland Zamia, called “Zamia sp. Punta Valiente”, also circulated among amateurs in 2012 and should not be confused with those from the island, although Vannini (2019) includes the plants of the Valiente Peninsula in Zamia hamannii (see In the wild).

Taxonomy

Zamia hamannii is an accepted name according to The World List of Cycads and GBIF; POWO could not be consulted directly. The species was described in 2008 by Alberto S. Taylor, Jody L. Haynes and Greg Holzman in the Botanical Journal of the Linnean Society (158: 399–429), in a paper devoted to the Zamia skinneri complex of Central America. The paper fixes the application of the name Zamia skinneri to the plants with green new leaves on the coast of Bocas del Toro, and describes new species for populations previously placed under that name, among them Zamia imperialis, Zamia nesophila and Zamia hamannii. The authors delimited these species by the geographical separation of the populations and by comparing measurements of up to 50 plants in a dozen populations; they deliberately left out precise localities, as a conservation measure.

The type specimen (A.S. Taylor B., J.L. Haynes and G. Holzman ASTB04-ZE1) was collected on 18 September 2004 in Bocas del Toro, on a small scrub-covered hill near the shore, at 2 m above sea level; the holotype is kept at the herbarium of the University of Panama (PMA), with isotypes at MO, NY, US and XAL.

Etymology and history

The species honours Gregg Hamann, of San Diego (California), who discovered it and funded the expedition during which most of the data and specimens used to describe it were gathered (Taylor and colleagues, 2008; Haynes, 2022).

Its seeds reached European collections through amateurs. In November 2012, a French grower back from a journey to Central America distributed free of charge to members of the Fous de palmiers forum about a hundred seeds of Zamia hamannii, collected on the island after finding a boat to take him there. Vannini (2019) notes that wild-collected seed was still being marketed more or less every year, but that plants from artificial propagation had begun to reach horticulture.

Common names

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

In the wild

The World List of Cycads gives only the province of Bocas del Toro. According to Panama’s environment ministry (MiAmbiente), quoted by the television channel TVN in April 2022, the species grows only on the island of Escudo de Veraguas, a protected area created in 2009 and managed by the ministry’s office for the Ngäbe-Buglé comarca, where it occurs naturally in coastal areas. Vannini (2019) gives a slightly broader picture: a micro-endemic, littoral and coastal species found along the length of the Valiente Peninsula and on adjacent offshore islets, in places occasionally submerged by seawater. The original description deliberately omits precise localities, so the two statements cannot be checked against it.

The type was collected on a hill close to the shore, at 2 m. According to the original description, it is an island and coastal species of low elevation, which often grows on steep slopes in humid tropical forest near the sea, sometimes overhanging the waves, but also in beach sand; its trunks are sometimes partly submerged by the Caribbean Sea, which makes it one of the few tree-forming Zamia truly tolerant of seawater (Taylor and colleagues, 2008).

Soils and climate. On the slopes, the soil is a layer of acid humus over soft mudstone; a little further inland, the basalt hills are also covered with acid humus. The plants grow there among climbers, heliconias and large trees, in a cool, shady and humid setting. On the beaches, in small coves that are sheltered but reached by storms, the “soil” is a basic calcareous sand; plants are fewer there, in full sun, with shorter leaves and trunks, and reproduce much less well. The climate of Bocas del Toro is tropical, with rainfall fairly even throughout the year; the soil is rarely dry (Taylor and colleagues, 2008).

Reproduction. The cones probably appear around May or June; pollen is shed and the female cones are receptive in September and October, and the seeds take about twelve months to ripen. Many beetles of the genus Pharaxonotha were found in the male cones, without direct proof of pollination for this species. Most seedlings grow beneath the parent plant or within a metre of it; for the beach plants, the authors suggest that land crabs disperse the seeds (Taylor and colleagues, 2008).

Populations. In 2008 the two known subpopulations numbered about 1,000 plants of all ages, 90 per cent of them on the humus-covered slopes, perhaps a few hundred of them adults, over less than 1 km² (Taylor and colleagues, 2008).

Conservation status and regulation

Zamia hamannii is rated Vulnerable (VU) on the IUCN Red List, in the 2022 assessment by Alberto Taylor-Blake, Jody Haynes and Greg Holzman, under criteria D1+2: a very small population, or one restricted to a very small area or number of locations (The World List of Cycads; GBIF gives the same category; the Red List itself could not be consulted). In 2008 the authors recommended Critically Endangered (CR B1ab(ii,iii,v)+2ab(ii,iii,v)), since a single population was known, over less than 1 km²; they recorded no collecting for trade at the time, the population being isolated and hard to reach, but named possible tourist development as a threat (Taylor and colleagues, 2008).

Collecting is a real threat. In April 2022, during a patrol in the Escudo de Veraguas-Degó protected area, MiAmbiente intercepted four people, two Panamanians and two Americans, on a boat carrying seven plants of Zamia hamannii and other plants taken without authorisation; administrative proceedings were opened and the case referred to the courts. In Panama, collecting the species in the wild is prohibited without a ministry permit.

Like all Zamia except Zamia restrepoi, which is in Appendix I, Zamia hamannii is covered by the listing of the genus in CITES Appendix II, in force since 4 February 1977. International trade in live plants is allowed but requires an export permit from the country of origin. Annotation #4 exempts in particular seeds, pollen, and seedlings or tissue cultures obtained in vitro and transported in sterile containers. 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: importing live plants requires a permit.

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 hamannii

Zamia hamannii is grown by specialist collectors, always in warm conditions. Vannini (2019), who grows a good number of plants from two separate sites, finds it slower-growing than Zamia imperialis and adds that it seems to need warm nights and warmer days to thrive; he also notes that it is popular with collectors and now available as artificially propagated material in Australia, south-east Asia and the United States.

In France it has been grown, mostly under glass, since 2013 from the seeds distributed on the Fous de palmiers forum. The grower who had collected them gave the following advice in 2012 and 2013: no full sun (the species tolerates a little sun, less than Zamia nesophila), partial to full shade, warmth, high air humidity to obtain large leaves but with moving air, and a free-draining compost kept moist. Too much light yellows the foliage of the Zamia of this group. He kept his own plants in a conservatory at about 21 °C (69.8 °F) all year.

This is amateur advice, consistent with the humid island habitat of the species, but no published data confirm it.

Outdoor and in-ground cultivation

Outdoor cultivation is only conceivable in a frost-free, humid tropical climate. Vannini (2019) illustrates a group of sunlit young plants flushing new leaves in a private collection in north-eastern Queensland, Australia. In Europe, the only reports are of young plants planted out in shade on the French Mediterranean coast in 2014 and of plants grown in the ground in Greece, known at second hand (see Cold hardiness).

Container cultivation

In temperate climates it is a plant for a heated glasshouse or conservatory: a free-draining compost kept moist, partial shade, high humidity with good air movement, and warmth by night as well as by day. Its large leaves, which exceed 2 m in mature plants, eventually require a lot of space.

In cultivation in the UK, US and Australia

In short: held by an American collection since 2004, declared by several American gardens and by Sydney; no British record.

  • United States: Montgomery Botanical Center (Coral Gables, Florida) lists five accession numbers under Zamia hamannii in its online catalogue, all from 2004, plus one plant recorded as Zamia aff. hamannii (2005). BGCI also records it at San Diego Botanic Garden (Encinitas, California), the University of Hawaii at Hilo and the National Tropical Botanical Garden (Kalāheo, Hawaii) (queried on 25 October 2026).
  • United Kingdom: no record in BGCI or in the online catalogues of British gardens.
  • Australia: the Royal Botanic Garden Sydney lists it in its online catalogue (Garden Explorer, updated on 1 October 2026) and declares it to BGCI; Vannini (2019) shows plants in a private collection in north-eastern Queensland.

A BGCI declaration shows that a garden held the plant at some point, not that it is alive there today, and the sources do not say whether these plants are grown outdoors or under glass.

Propagation

Seed is the only documented method, and it works well. According to the members of the Fous de palmiers forum who received seeds at the end of 2012, Zamia hamannii germinates very quickly, like the other Zamia with veined leaflets, and soon produces its first leaf, unlike Zamia lindenii. A grower in the Gard, in southern France, reports on the Fous de palmiers forum that his first seed germinated on 7 January 2013, about twelve days after sowing on 26 December 2012, at 28 to 29 °C (82.4 to 84.2 °F). Other members (around Nantes and in the Dordogne) reported germination in mid-January 2013; another counted, in March, two seeds germinated out of five, two rotted and one with no reaction.

The grower who distributed them germinated his seeds on moist vermiculite, above water heated to about 25 °C (77 °F) by an aquarium heater, then planted them in a very sandy compost, half buried and upright, as soon as the root reached about 1 cm. He recommended sowing above 20 °C (68 °F) without letting the compost dry out.

Pests and diseases

The only problem reported concerns sowing: in January 2013 a grower in the Dordogne reported a mould spreading over a tray of Zamia hamannii despite sterilisation, which he attributed to remnants of the red fleshy coat of the seeds, which had not been cleaned. Carefully removing the sarcotesta before sowing limits this risk. In the wild, large stinging ants shelter in the leaf bases and defend the plant, with no herbivore damage observed; a leaf spot caused by a fungus close to Mycoleptodiscus indicus affects a few sun-exposed beach plants without notable effect, whereas in cultivation this fungus can quickly destroy untreated seedlings and young plants (Taylor and colleagues, 2008).

Cold hardiness

No reliable data exist on the cold tolerance of Zamia hamannii. It is a lowland species from a humid tropical coast, and the only growing advice published stresses its need for warmth (Vannini, 2019).

Mediterranean and European experience

A grower on the Côte Bleue, the coast west of Marseille (Bouches-du-Rhône, France), reports on the Fous de palmiers forum that he planted out his young plants of Zamia hamannii, raised from the seeds distributed at the end of 2012, in summer 2014, in a humid, shady spot among tropical foliage, alongside Zamia nesophila and Zamia lindenii; in January 2015 they “seemed to be getting through” the winter, and in September 2015 he wrote that they had come through the winter of 2014–2015 “without trouble”. He gives no temperature: the nearest Météo-France station, Marignane, recorded a minimum of −3.0 °C (26.6 °F) on 10 February 2015, but it is not on the coast, and the temperature the plants actually experienced is unknown. No later report says how they fared. In February 2015 the grower who had distributed the seeds added, on the same forum, that a correspondent in Greece grew Zamia hamannii in the ground, under a tree canopy, in an area with minimums of −2 to −2.5 °C (28.4 to 27.5 °F): the plants lose their leaves in winter and regrow in spring. This is a second-hand report, with no precise place or dated episode.

These are isolated amateur reports, and no dated frost episode concerns the species. The other French growers who sowed it in 2012–2013 (in the Gard, the Dordogne, around Nantes, and in the Ain or the Hérault) keep it in a glasshouse or heated conservatory. For readers in Mediterranean-type climates such as California or southern Australia, as in the UK, it remains essentially a plant for heated glass: as the seed distributor warned, a defoliated plant recovers but is set back.

United Kingdom, United States and Australia

No cold record has been published. The gardens that declare it are in southern Florida, coastal southern California, Hawaii and Sydney, and a private collection grows it in north-eastern Queensland (Vannini, 2019); none of these sources says whether the plants are outdoors or under glass. In the UK it needs a heated glasshouse all year.

Toxicity and precautions

No toxicity study specific to Zamia hamannii 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 use is documented with certainty: in 2008 the authors recorded plants that had been cut by people and had formed a new bud, perhaps for a medicinal use like that of Zamia nesophila on other islands of Bocas del Toro (Taylor and colleagues, 2008). MiAmbiente stresses the ornamental appeal of the species, which drives illegal collecting.

Frequently asked questions

Where does Zamia hamannii grow?

On the Caribbean coast of western Panama, in the Bocas del Toro region: on the island of Escudo de Veraguas according to Panama’s environment ministry, and along the Valiente Peninsula and nearby islets according to Vannini (2019), in forest near the shore and down to the beaches.

How big does it get?

It is large for a Zamia. Its trunk reaches 2.4 m (commonly 2 m) and 20 cm in diameter, and its leaves more than 2 m, with leaflets up to 62 cm long and 14 cm wide (Taylor and colleagues, 2008).

Why “hamannii”?

In honour of Gregg Hamann, of San Diego, who discovered the species and funded the expedition that made its description possible.

How can it be told from Zamia skinneri?

Mainly by the new leaves: bright green and hairless in Zamia skinneri, pinkish brown to orange-pink and covered in silvery down in Zamia hamannii, which also has longer leaflets and more globose seeds (Taylor and colleagues, 2008). Provenance helps too.

Is it endangered?

Yes. It has been rated Vulnerable (VU) by the IUCN since 2022: a very restricted range, small populations, and illegal collecting (seven plants seized in 2022).

Do the seeds germinate easily?

Yes, according to French amateurs: rapid germination at 25 to 29 °C (77 to 84.2 °F) and a first leaf soon produced. Clean off the red seed coat thoroughly to avoid mould.

Can it be grown outdoors?

Reliably, only in a frost-free, humid tropical climate; a private collection in north-eastern Queensland grows it (Vannini, 2019). On the French Mediterranean coast, young plants came through the winter of 2014–2015 in the ground, in shade, but this is an isolated amateur report. Elsewhere it needs a heated glasshouse or conservatory, partial shade and humid air.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Taylor, A.S., Haynes, J.L. & Holzman, G. (2008). Taxonomical, nomenclatural and biogeographical revelations in the Zamia skinneri complex of Central America (Cycadales: Zamiaceae). Botanical Journal of the Linnean Society 158(3): 399–429. https://doi.org/10.1111/j.1095-8339.2008.00886.x [Protologue; full text read: description, type, habitat and soils, phenology, pollination, pests, populations, proposed status.]
  • 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.]
  • Taylor-Blake, A., Haynes, J. & Holzman, G. (2022). Zamia hamannii. The IUCN Red List of Threatened Species 2022: e.T187836A1828804. [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.]