Berberidopsidales Doweld

1. Supertaxonomy Overview

Berberidopsidales Doweld is a small but evolutionarily important order of woody flowering plants within the superasterids. In its modern circumscription it contains just two families, Aextoxicaceae and Berberidopsidaceae, comprising three genera and five accepted living species. Those few species span a remarkable range of forms: the Olivillo Family is represented solely by the evergreen South American forest tree Aextoxicon punctatum, while the Coralplant Family includes the woody climbers and scrambling shrubs of Berberidopsis and Streptothamnus, together with the recently described low, stoloniferous Berberidopsis granitica. The order is confined to southern South America and eastern Australia.

Its significance is therefore almost the inverse of its species richness. Berberidopsidales preserves two deeply divergent family lineages whose relationship was difficult to recognize from outward appearance and only became clear with molecular systematics. The order also occupies an important position near the base of the superasterid radiation, where comparisons among nuclear, plastid, mitochondrial, morphological, and developmental evidence continue to illuminate one of the earliest phases in the evolution of the enormous asterid-centered branch of the flowering-plant tree.

The accepted ordinal name was published by Alexander Doweld in 2001. APG II acknowledged that Aextoxicon and Berberidopsidaceae were closely related and noted that the name Berberidopsidales was available, but left the two families unplaced to order because their broader relationships remained uncertain. APG III formally recognized Berberidopsidales in 2009, and APG IV subsequently placed it among the superasterids. World Flora Online continues to recognize Berberidopsidales Doweld, with Aextoxicaceae and Berberidopsidaceae as its two included families.

2. Placement in Tree TSAR

Tree TSAR treats Berberidopsidales as a direct major branch of the Superasterids, linking that large flowering-plant clade downward to Aextoxicaceae and Berberidopsidaceae. This arrangement follows the stable ordinal circumscription established by APG III and APG IV. The 2026 APG V update reports that most of the APG IV framework remains supported by modern nuclear and plastid phylogenomics and identifies only a limited set of ordinal changes; Berberidopsidales is not among the orders whose circumscription was revised.

Its precise branching position within the early superasterids is less settled than the order itself. Large nuclear datasets have recovered Berberidopsidales as the strongly supported sister lineage of the asterids, whereas comprehensive plastid analyses have placed Santalales, Berberidopsidales, and Caryophyllales as successive sister groups leading toward the asterids. A 2025 mitochondrial phylogenomic analysis produced an even more divergent result, moderately supporting Berberidopsidales as sister to the remaining core eudicots. The latter topology differs from most nuclear and plastid studies and has not displaced the superasterid placement in the working angiosperm classification.

This distinction is useful. The existence and circumscription of Berberidopsidales are well supported; uncertainty concerns where the entire order attaches to neighboring deep branches. For Tree TSAR, retaining the order under Superasterids provides both a stable classification and an honest framework for explaining this continuing phylogenomic question.

3. Evolutionary History and Fossil Context

Molecular dating suggests a considerable evolutionary history hidden behind the order’s tiny modern diversity. Menegoz et al. (2024), using nuclear and chloroplast evidence across every living species then recognized in Berberidopsidales plus the newly described Berberidopsis granitica, estimated the split between Aextoxicaceae and Berberidopsidaceae at roughly 62 million years ago. The confidence intervals are broad, however, in part because the order lacks secure fossils suitable for direct calibration. Its two living family lineages can therefore be regarded as ancient, but individual molecular dates should not be treated as exact measures of their origin.

The fossil record itself is tantalizing rather than definitive. Fossil woods assigned to Aextoxicoxylon have been reported from southern South America, including Aextoxicoxylon kawasianus from Upper Cretaceous deposits of Patagonia. Their anatomy provides evidence of extinct woody plants with features reminiscent of the lineage, but Aextoxicoxylon is an anatomically defined fossil genus rather than an extinct species of Aextoxicon. It therefore cannot simply be inserted into the crown group of living Aextoxicaceae or used to push the securely demonstrated age of modern Berberidopsidales into the Cretaceous.

The living distribution has its own evolutionary surprise. The separation between Chilean and Australian Berberidopsis might superficially suggest a Gondwanan vicariance story, but the dated phylogeny places their divergence only around the late Miocene to Pliocene. That is vastly younger than the breakup of Gondwana. Long-distance trans-Pacific dispersal is consequently a much more plausible explanation for the modern disjunction, while the still deeper separation between Berberidopsis and Australian Streptothamnus represents a different and older component of the order’s history.

4. Classification and Circumscription

The modern circumscription of Berberidopsidales is unusually stable:

Aextoxicaceae Engl. & Gilg, the Olivillo Family, contains only Aextoxicon punctatum. Berberidopsidaceae (Veldkamp) Takht., the Coralplant Family, contains Berberidopsis and Streptothamnus. Current Kew treatments accept one genus in Aextoxicaceae and two in Berberidopsidaceae.

The species total requires an update from much of the older literature. Until 2024, treatments commonly described Berberidopsidales as an order of four living species. Menegoz, Villarroel & Lavandero added Berberidopsis granitica from the central Chilean Andes, bringing the currently recognized complement to five species: one Aextoxicon, three Berberidopsis, and one Streptothamnus. Their combined nuclear and chloroplast analyses also strongly supported the existing two-family structure and the distinction of Streptothamnus from Berberidopsis.

This modern classification resolves a long history of uncertainty. Aextoxicon had been associated with such unrelated groups as Elaeagnaceae and Euphorbiaceae, while Berberidopsis and Streptothamnus spent much of their taxonomic history in the heterogeneous former Flacourtiaceae. Their eventual union in Berberidopsidales is a striking example of molecular phylogenetics revealing a relationship that gross morphology alone did not make obvious.

5. Morphology, Biology, and Identification

Berberidopsidales is not an order that can be recognized at a glance by one conspicuous field character. Its two families look remarkably different. Aextoxicon punctatum is a dioecious evergreen tree with opposite, entire leaves bearing distinctive peltate scales, pendulous racemes of unisexual flowers, and dark drupaceous fruits. Berberidopsidaceae is predominantly composed of evergreen woody climbers or scrambling shrubs with alternate leaves, although B. granitica breaks that pattern as a compact stoloniferous shrub.

Anatomy provides some of the evidence that outward appearance conceals. Carlquist’s comparative study found numerous similarities between the woods of Aextoxicaceae and Berberidopsidaceae, including long vessel elements and tracheids, scalariform or transitional vessel pitting, diffuse axial parenchyma, heterogeneous rays, and other comparatively conservative xylem features. Some ray characters and dark-staining deposits were proposed as particularly informative shared features. These observations independently complemented the molecular evidence linking the two families.

Flowers make Berberidopsidales especially important in studies of angiosperm evolution. Berberidopsis retains a predominantly spiral sequence of tepals and other floral organs, yet the developmental pattern contains an underlying regularity related to the five-part architecture characteristic of core eudicot flowers. Ronse De Craene interpreted B. corallina as unusually informative for understanding the transition from spiral floral construction toward the strongly whorled, pentamerous flowers that dominate many major core-eudicot lineages. The very different flowers of Aextoxicon and Streptothamnus demonstrate how extensively floral organization has diverged during the long history of this species-poor order.

6. Distribution and Ecology

All living Berberidopsidales are Southern Hemisphere woody plants, and their distribution is restricted to temperate or subtropical parts of South America and eastern Australia. Aextoxicaceae occurs in Chile and southwestern Argentina. Berberidopsidaceae has a remarkable trans-Pacific distribution: Berberidopsis corallina and B. granitica are Chilean endemics, whereas B. beckleri and Streptothamnus moorei occur in eastern Australia.

Moist forest is the ecological thread running through much of the order. Aextoxicon punctatum can become a major canopy tree in Chilean temperate rain forest and also persists in extraordinary fog-dependent relict forests at the dry northern limit of its range. Berberidopsis corallina inhabits humid Chilean forests, while the Australian taxa are associated with eastern rain forests. Berberidopsis granitica is the major exception: it occurs around 1,600 m in the central Chilean Andes, growing among granite outcrops in montane Mediterranean vegetation above or near the treeline. Menegoz et al. described this environment as unique within the order.

The order consequently combines strong geographic restriction with striking ecological breadth relative to its mere five species. That contrast is particularly useful for understanding how small relict lineages can retain substantial evolutionary and functional diversity even after most of their historical species diversity has disappeared or remains unknown from the fossil record.

7. Human Uses and Cultural Importance

Berberidopsidales has little importance as a major agricultural or commodity-producing group, but individual species have meaningful regional uses. Andean olivillo (Aextoxicon punctatum) has historically supplied timber and fuel in Chile, and its wood was used for construction and other local purposes. Historical exploitation contributed to losses in some parts of the species’ central and northern range.

Berberidopsis corallina is the principal ornamental representative of the order. Its evergreen foliage and pendant deep-red flowers have made red coralplant a specialist garden climber in mild oceanic climates. Its flexible stems have also traditionally supplied fiber for Chilean handicrafts. These uses are culturally significant because the same species is now endangered in the wild and survives largely in fragmented remnants of native coastal forest.

The remaining species have little established commercial importance, which is appropriate context rather than a deficiency: much of the value of Berberidopsidales lies in evolutionary history, ecological distinctiveness, and conservation rather than in large-scale economic exploitation.

8. Conservation Significance

The order’s tiny living diversity makes losses especially consequential. Of only five species, several represent unusually isolated evolutionary branches, and extinction can therefore remove a disproportionate amount of phylogenetic history.

The strongest immediate concerns occur in Chile. Berberidopsis corallina is classified nationally as Endangered, with habitat loss, plantation forestry, fragmentation, grazing, and invasive vegetation among the major pressures on its remaining populations. B. granitica is known from only one extremely restricted Andean locality and was described with a proposed Critically Endangered status.

The picture for Aextoxicon punctatum varies geographically. The species remains widespread and abundant through substantial portions of southern Chile and Argentina, but Chile classifies its northern populations from the Metropolitan Region northward as Vulnerable, while populations from O’Higgins southward are Least Concern. The isolated northern forests are threatened particularly by drought, water extraction, development, fire, and habitat degradation. Their genetic and biogeographic distinctiveness makes conservation of those populations important even though the species as a whole is much more secure.

The Australian members currently face less acute recognized extinction risk, but conserving them remains important because Streptothamnus moorei represents an entire genus and one of the two deep branches of Berberidopsidaceae.

9. Major Included Groups

The order divides cleanly into two living family lineages.

Aextoxicaceae — Olivillo Family. This family contains only Aextoxicon punctatum, an evergreen South American forest tree. It is morphologically distinctive enough that its relationship to Berberidopsidaceae remained obscure until molecular evidence brought the two together.

Berberidopsidaceae — Coralplant Family. This family contains Berberidopsis and Streptothamnus. Berberidopsis comprises three species divided between Chile and Australia, while Streptothamnus contains only the Australian S. moorei. The two genera are deeply divergent, morphologically diagnosable, and strongly supported as separate lineages by modern molecular analyses.

Together, these families form a far more convincing evolutionary unit than their contrasting appearances initially suggest.

10. Similar, Overlapping, or Historically Confused Groups

Despite its name, Berberidopsidales is not closely related to Berberidaceae, the Barberry Family. The resemblance is nomenclatural and historical: Berberidopsis was named for a superficial resemblance to Berberis, whereas Berberidaceae belongs much farther away in Ranunculales.

Historical placements can also be misleading. Berberidopsis and Streptothamnus were formerly included in the broad Flacourtiaceae, while Aextoxicon was at various times associated with Elaeagnaceae, Euphorbiaceae, and other unrelated groups. None represents its modern phylogenetic position.

Older literature also commonly describes Berberidopsidales as lying “at the base of the core eudicots.” That phrasing reflects the uncertainty prevailing before the superasterid framework became established and should not be read as implying that the order lies outside the core eudicots. Modern Tree TSAR placement is Core Eudicots → Superasterids → Berberidopsidales, while acknowledging that its precise relationship to Caryophyllales, Santalales, and the asterids varies among genomic datasets.

11. Additional Information

World Flora Online — Berberidopsidales Doweld (opens in a new tab) — Current order-level nomenclatural record and two-family circumscription.

Kew Tree of Life Explorer (opens in a new tab) — Genomic phylogenetic resources for flowering plants, including Berberidopsidales.

APG V — Journal of Systematics and Evolution (opens in a new tab) — Current Angiosperm Phylogeny Group classification incorporating large nuclear and plastid phylogenomic datasets.

12. References and Further Reading

Angiosperm Phylogeny Group (2009) An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III. Botanical Journal of the Linnean Society 161: 105–121. https://doi.org/10.1111/j.1095-8339.2009.00996.x (opens in a new tab).

Angiosperm Phylogeny Group (2016) An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV. Botanical Journal of the Linnean Society 181: 1–20. https://doi.org/10.1111/boj.12385 (opens in a new tab).

Angiosperm Phylogeny Group, Byng JW, Chase MW, Christenhusz MJM, Fay MF, Li D-Z, Ma H, Mabberley DJ, Soltis DE, Soltis PS, Stevens PF, Baker WJ, Dodsworth S, Forest F, Maurin O, Pokorny L, Smith SA & Zuntini AR (2026) Large-scale nuclear and plastid phylogenomic analyses inform an updated Angiosperm Phylogeny Group classification: APG V. Journal of Systematics and Evolution. Online 18 June 2026.

Carlquist S (2003) Wood anatomy of Aextoxicaceae and Berberidopsidaceae is compatible with their inclusion in Berberidopsidales. Systematic Botany 28(2): 317–325. https://doi.org/10.1043/0363-6445-28.2.317 (opens in a new tab).

Li H-T, Luo Y, Gan L, Ma P-F, Gao L-M, Yang J-B, Cai J, Gitzendanner MA, Fritsch PW, Zhang T, et al. (2021) Plastid phylogenomic insights into relationships of all flowering plant families. BMC Biology 19: 232. https://doi.org/10.1186/s12915-021-01166-2 (opens in a new tab).

Menegoz K, Villarroel AE & Lavandero N (2024) Phylogeny of Berberidopsidales based on nuclear and chloroplast loci, with the description of a new species of Berberidopsis endemic to Central Chile. Taxon 73: 800–817. https://doi.org/10.1002/tax.13170 (opens in a new tab).

Moore MJ, Soltis PS, Bell CD, Burleigh JG & Soltis DE (2010) Phylogenetic analysis of 83 plastid genes further resolves the early diversification of eudicots. Proceedings of the National Academy of Sciences of the United States of America 107: 4623–4628. https://doi.org/10.1073/pnas.0907801107 (opens in a new tab).

Ronse De Craene LP (2004) Floral development of Berberidopsis corallina: a crucial link in the evolution of flowers in the core eudicots. Annals of Botany 94: 741–751. https://doi.org/10.1093/aob/mch199 (opens in a new tab).

Ronse De Craene LP & Stuppy W (2010) Floral development and anatomy of Aextoxicon punctatum (Aextoxicaceae-Berberidopsidales): an enigmatic tree at the base of core eudicots. International Journal of Plant Sciences 171: 244–257. https://doi.org/10.1086/650161 (opens in a new tab).

Vera EI, Perez Loinaze VS, Llorens M & Passalia MG (2020) The fossil genus Aextoxicoxylon (Magnoliopsida) in the Upper Cretaceous Puntudo Chico Formation, Chubut Province, Argentina. Cretaceous Research 107: 104315. https://doi.org/10.1016/j.cretres.2019.104315 (opens in a new tab).

Zhang C, Zhang T, Luebert F, Xiang Y, Huang C-H, Hu Y, Rees M, Frohlich MW, Qi J, Weigend M & Ma H (2020) Asterid phylogenomics/phylotranscriptomics uncover morphological evolutionary histories and support phylogenetic placement for numerous whole-genome duplications. Molecular Biology and Evolution 37: 3188–3210.