Zamia brasiliensis is a small, subterranean-stemmed cycad of the family Zamiaceae, endemic to the states of Mato Grosso and Rondônia in western Brazil. Described as recently as 2019 by Rosane Segalla and Michael Calonje, it holds a singular distinction: Zamia brasiliensis is the only species of Zamia endemic to Brazil, a remarkable fact given the country’s extraordinary botanical diversity. The species grows in the poorly explored transition zone between two of South America’s greatest biomes — the Cerrado savanna and the Amazon rainforest — a frontier that continues to yield new cycad discoveries. The genus Zamia comprises over 80 recognized species distributed across the Americas.
The accepted name Zamia brasiliensis Calonje & Segalla follows the nomenclatural authority of POWO (Plants of the World Online, Royal Botanic Gardens, Kew). The species was described in Phytotaxa (vol. 404, 2019) from material collected in the municipality of Itaúba, Mato Grosso, during field expeditions in 2018. The specific epithet brasiliensis directly references the species’ restricted distribution within Brazil. Prior to its formal description, specimens of this species had been collected in Mato Grosso and Rondônia over several decades but remained undetermined in herbaria or were misidentified as Zamia ulei, an Amazonian species with superficially similar juvenile leaflets.
Taxonomy and Phylogenetic Position
A Species Hidden in Plain Sight
The story of Zamia brasiliensis illustrates a recurring theme in cycad taxonomy: species that evade formal description for decades because they are mistaken for something else. Several Zamia specimens from the Cerrado-Amazon transition zone had accumulated in Brazilian herbaria since the 1980s, often filed under Zamia ulei Dammer (1907) — a genuine Amazonian species with similar-looking leaflets in its juvenile stage. It was not until Segalla and Calonje conducted targeted field expeditions in 2018 and closely examined both vegetative and reproductive morphology that the distinct identity of these populations was confirmed.
The misidentification with Zamia ulei is understandable at first glance: young plants of Zamia ulei produce broad, elliptic leaflets that resemble those of Zamia brasiliensis. However, adult Zamia ulei develops much larger overall dimensions and — critically — has conspicuously prickly petioles, whereas Zamia brasiliensis has completely smooth, unarmed petioles throughout its life cycle.
Position in the South American Clade
Molecular phylogenetic work by Calonje et al. (2019) and Lindstrom et al. (2024) places Zamia brasiliensis within the Amazonian Clade of the South American Zamia species. This clade includes Zamia boliviana, Zamia poeppigiana, Zamia macrochiera, Zamia hymenophyllidia, Zamia amazonum, and Zamia urep. Within this group, Zamia brasiliensis appears most closely related to Zamia boliviana from the neighboring Cerrado biome, with which it shares the rare trait of completely unarmed petioles.
The Amazonian Clade represents the southern and eastern frontier of the genus Zamia, with species distributed across Bolivia, Brazil, Peru, and Ecuador in a mix of rainforest, savanna, and transitional habitats.
Natural Habitat and Distribution
Zamia brasiliensis is known from two populations in the states of Mato Grosso and Rondônia, western Brazil. The type locality is in the municipality of Itaúba, Mato Grosso. The species occupies a very specific ecological niche: submontane semi-deciduous forest in the transition zone between the Cerrado and the Amazon rainforest.
This transitional habitat is characterized by a mosaic of forest types: patches of semi-deciduous tropical forest (where many trees lose their leaves during the dry season) interspersed with Cerrado savanna enclaves and pockets of denser, more humid Amazonian forest. The soils are well-drained, and the climate is tropical with a distinct dry season lasting several months.
The transition zone between the Cerrado and the Amazon is one of the most actively deforested frontiers in South America. The “arc of deforestation” — the crescent-shaped zone where agricultural expansion pushes into the southern and eastern edges of the Amazon — passes directly through the known range of Zamia brasiliensis. This geographic position makes the species inherently vulnerable to habitat loss.
Morphological Description
General Habit and Stem
Zamia brasiliensis is a small, dwarf cycad with a subterranean stem. The caudex remains entirely underground, and only the leaves and reproductive cones emerge above the soil surface. This underground growth habit is shared with its close relative Zamia boliviana and provides protection against the fires that periodically sweep through the semi-deciduous forest and adjacent Cerrado vegetation.
Leaves and Leaflets
The crown bears a modest number of compound leaves. The leaves can reach up to approximately 80 to 100 cm in length. The petioles are smooth and completely unarmed — lacking any prickles or spines throughout their length. This is a key diagnostic character shared only with Zamia boliviana among South American mainland zamias.
Each leaf carries 16 to 40 leaflets. The leaflets are elliptic to oblong, significantly broader than those of Zamia boliviana — this difference in leaflet width is the single most important morphological character separating the two species. The leaflet texture is chartaceous (papery), and the margins bear small serrations, particularly toward the tips. The leaflets taper to an acuminate (pointed) apex.
The relatively broad, flat leaflets give Zamia brasiliensis an elegant, fern-like appearance that resembles the juvenile foliage of Zamia ulei. However, unlike Zamia ulei, which develops into a much larger, arborescent plant with prickly petioles at maturity, Zamia brasiliensis remains a small, subterranean-stemmed species throughout its life.
Reproductive Structures
Zamia brasiliensis is strictly dioecious. Male plants produce pollen strobili (cones) that are covered in yellow-cream tomentum, with the sterile apex distinctly covered in orange-brown tomentum — a diagnostic character that distinguishes them from the solid yellow-cream tomentum of Zamia boliviana pollen cones.
Female plants produce a single megastrobilus (seed cone) per crown. The cones are cream-tan with green undertones or cream-yellow to tan. Seeds are enclosed in a red-orange sarcotesta at maturity, consistent with the typical Zamia seed morphology.
Pollination is presumed to be entomophilous (insect-mediated), carried out by beetles, as in all other Zamia species studied. Specific pollinator species for Zamia brasiliensis have not yet been documented, though Pharaxonotha beetles are known pollinators of the closely related Zamia boliviana.
Root System
Coralloid roots housing nitrogen-fixing Nostoc cyanobacteria are present, as in all cycads. This symbiosis is particularly important in the nutrient-poor transitional soils where the species occurs.
Zamia brasiliensis vs. Zamia boliviana: Telling Apart Two Sister Species
Zamia brasiliensis and Zamia boliviana are the two most closely related Zamia species in South America. They share the rare trait of unarmed petioles, subterranean stems, and broadly similar reproductive morphology. Their distributions are adjacent but non-overlapping: Zamia boliviana occupies the open Cerrado savanna to the west, while Zamia brasiliensis occurs in the semi-deciduous transitional forest to the east.
Despite their close relationship, the two species are readily distinguishable:
| Feature | Zamia brasiliensis | Zamia boliviana |
|---|---|---|
| Distribution | Mato Grosso, Rondônia (Brazil) | N. Bolivia, W. Brazil (Mato Grosso) |
| Habitat | Semi-deciduous transitional forest | Cerrado savanna, open woodland |
| Leaflet width | Broad (elliptic to oblong) | Narrow, 1.1–2.0 cm (linear-lanceolate) |
| Leaflet shape | Elliptic, with acuminate tip | Linear-lanceolate, tapering |
| Pollen cone apex tomentum | Orange-brown | Solid yellow-cream |
| Megastrobilus peduncle | Longer | Shorter |
| Petiole | Unarmed | Unarmed |
| Stem | Subterranean | Subterranean |
| IUCN status | Endangered (proposed) | Least Concern (LC) |
The fastest identification cue is leaflet width: broad, elliptic leaflets indicate Zamia brasiliensis; narrow, grass-like, linear-lanceolate leaflets indicate Zamia boliviana. The tomentum color on the pollen cone apex (orange-brown in Zamia brasiliensis vs. solid yellow-cream in Zamia boliviana) provides a secondary diagnostic when reproductive material is available.
A third related species, Zamia ulei, is distinguished from both by its conspicuously prickly petioles — the presence of prickles immediately separates Zamia ulei from the two unarmed-petiole species. Zamia ulei also grows into a much larger, arborescent plant at maturity.
Conservation Status
Zamia brasiliensis was described with the explicit note that it qualifies as an Endangered species under IUCN Red List criteria. Its known distribution is limited to two populations in the states of Mato Grosso and Rondônia, placing it in one of the most intensively deforested regions on Earth.
Threats
Deforestation is the overwhelming threat. The Cerrado-Amazon transition zone in Mato Grosso and Rondônia has experienced catastrophic rates of forest loss since the 1990s, driven by soybean cultivation, cattle ranching, and logging. Between 2001 and 2020, Mato Grosso was consistently among the most deforested states in Brazil. The semi-deciduous forest habitat where Zamia brasiliensis occurs is particularly vulnerable because it is perceived as less valuable than primary Amazonian rainforest and is often cleared with minimal regulatory resistance.
Small number of known populations. Only two populations were documented at the time of the species’ description. Additional populations may exist in unexplored areas of the transition zone, but targeted surveys are urgently needed.
Misidentification. The species’ long confusion with Zamia ulei means that its conservation needs were invisible for decades. Specimens sitting in herbaria were attributed to a different species, masking the existence and rarity of Zamia brasiliensis.
Illegal collection for the ornamental trade is a potential threat, though the species’ limited availability in cultivation currently means that horticultural demand has not yet become a significant factor.
Conservation Measures
Zamia brasiliensis is covered under CITES Appendix II as part of the broader protection afforded to all Zamiaceae. National-level conservation measures in Brazil remain limited, and specific conservation plans for this species have not yet been developed.
The most urgent priorities are targeted field surveys to locate additional populations, formal assessment and listing on the IUCN Red List, and the establishment of ex situ collections in Brazilian botanical gardens (such as the Jardim Botânico do Rio de Janeiro and the Jardim Botânico de São Paulo) and international institutions (such as the Montgomery Botanical Center in Florida) to secure the species’ genetic diversity outside its threatened habitat.
The role of researcher Rosane Segalla (Instituto Federal de Educação, Ciência e Tecnologia de Mato Grosso) and Michael Calonje (Montgomery Botanical Center) in discovering, describing, and advocating for this species exemplifies the critical contribution of taxonomic research to cycad conservation. Without their fieldwork, Zamia brasiliensis would still be an unnamed entity hidden in herbarium folders, its conservation needs completely unrecognized.
Growing Zamia brasiliensis: Preliminary Care Guide
As a species described only in 2019, Zamia brasiliensis is virtually absent from cultivation. Cultivation data are extremely limited, and the following guidelines are extrapolated from the species’ known habitat and from experience with the closely related Zamia boliviana.
Light and Exposure
The semi-deciduous forest habitat suggests tolerance of partial shade to dappled light, with some exposure to direct sun during the dry season when the canopy thins. In cultivation, bright filtered light to partial sun is likely optimal.
Soil and Drainage
Excellent drainage is essential. Use a well-drained, mineral-rich substrate with moderate organic content — somewhat richer than the pure mineral mix recommended for the xeric Zamia boliviana, reflecting the species’ more mesic forest habitat. A slightly acidic to neutral pH is preferable.
Watering
The semi-deciduous forest environment receives seasonal rainfall with a distinct dry period. Water regularly during the growing season and reduce during the cool or dry dormant period. The subterranean caudex stores water reserves but is susceptible to rot in waterlogged conditions.
Temperature
No specific cold hardiness data are available. The species is tropical, growing in lowland to submontane situations. A cautious estimate would place it in the USDA 10a to 10b range (minimum −1 to 1.7 °C), comparable to Zamia boliviana. Frost-free greenhouse or conservatory culture is recommended in all non-tropical climates.
Container Culture
The small, subterranean-stemmed growth habit makes Zamia brasiliensis potentially well-suited to container culture. Use a well-drained mix in a terracotta pot. Given the species’ rarity, any cultivated specimen should be treated as a conservation asset.
Toxicity
All parts of Zamia brasiliensis are presumed toxic due to the presence of cycasin and related compounds, as in all Zamia species. Keep away from pets and children.
Frequently Asked Questions
Why was Zamia brasiliensis only described in 2019? The species was confused with Zamia ulei, an Amazonian cycad with similar-looking juvenile foliage. Specimens had been collected and deposited in herbaria for decades but remained misidentified. It took detailed field expeditions and careful comparative morphology to recognize it as a distinct species.
Is Zamia brasiliensis really the only Zamia endemic to Brazil? Yes. While Zamia boliviana and Zamia ulei also occur in Brazil, their ranges extend into Bolivia and other countries respectively. Zamia brasiliensis is the only species whose entire natural distribution is confined to Brazilian territory.
How do I tell Zamia brasiliensis apart from Zamia boliviana? Leaflet width is the key: Zamia brasiliensis has broad, elliptic leaflets, while Zamia boliviana has narrow, linear-lanceolate leaflets (1–2 cm wide). Both species have unarmed petioles. The pollen cone apex is orange-brown in Zamia brasiliensis and solid yellow-cream in Zamia boliviana.
Is Zamia brasiliensis available in cultivation? It is virtually unknown in cultivation as of the mid-2020s. Any plants that become available from legally sourced seed should be treated as conservation-priority material and cultivated with care.
Sources and Further Reading
- 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.
- Lindstrom, A. et al. (2024). Transcriptome sequencing data provide a solid base to understand phylogenetic relationships, biogeography and reticulated evolution of the genus Zamia L. Annals of Botany, XX: 10.
- Segalla, R. & Calonje, M. (2019). Zamia brasiliensis, a new species of Zamia (Zamiaceae, Cycadales) from Mato Grosso and Rondônia, Brazil. Phytotaxa, 404(1): 1–11.
- Segalla, R., Telles, F.J., Pinheiro, F. & Morellato, P. (2019). A Review of Current Knowledge of Zamiaceae, with Emphasis on Zamia from South America. Tropical Conservation Science, 12: 1–20.
- POWO (2026). Zamia brasiliensis Calonje & Segalla. Plants of the World Online. Royal Botanic Gardens, Kew. https://powo.science.kew.org/